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THE  COMPOSITION 

OF 

TECHNICAL  PAPERS 


5^  QrawOJlllBock  (h.  Im 

PUBLISHERS     OF     BOOKS     FOR-/ 

Coal  Age  -^  Electric  Railway  Journal 
Electrical  Ubrld  v  Engineering  News-Record 
Railway  Age  Gazette  ^  American  Machinist 
Electrical  Merchandising  ^  The  Contractor 
Engineering S Mining  Journal  v  Power 
Metallurgical  6  Chemical  Engineering 


Biniiiiiiiiniiiiiiiniiiiiniiinnmiiinifnniinfnnniniiiiiiiliiiiiii'iliiniillniiiil^ 


THE  COMPOSITION 

OF 

TECHNICAL  PAPEKS 


BY 
HOMER  ANDREW  WATT 

ASSISTANT    PB0FES80R    OF  ENGLISH,  NEW    YORK   UNIVEB8ITT 


First  Edition 


McGRAW-HILL  BOOK  COMPANY,  Inc. 
239  WEST  39TH  STREET.    NEW  YORK 


LONDON:  HILL  PUBLISHING  CO.,  Ltd. 

6  &  8  BOUVERIE  ST.,  E.  C. 
1917 


Copyright,  1917,  by  the 
McGraw-Hill  Book  Company,  Inc. 


THK  MAPI.B  PKKS8  YORK  PA 


PREFACE 

The  teaching  of  English  composition  to  engineering 
students  has  taken  two  directions,  one  liberal,  the  other 
professional.  The  first  of  these,  following  the  present 
trend  of  engineering  education  away  from  narrow  over- 
specialization,  aims  to  give  the  engineering  student 
substantially  the  same  course  which  is  given  his  brother 
in  the  liberal  arts  college,  with  the  difference,  sometimes, 
that  the  specimens  of  exposition  analyzed  in  class  and 
the  theme  subjects  assigned  are  meant  to  be  of  especial 
interest  to  engineers.  The  second  has  the  more  imme- 
diate aim  of  preparing  the  engineering  student  to  write 
successfully  such  papers  as  his  vocation  will  demand  of 
him.  The  first  regards  the  embryo  engineer  primarily 
as  a  future  member  of  society;  the  second  regards  him 
primarily  as  a  future  engineer.  The  division  between 
the  liberal  and  the  professional  aims  is  not,  in  the  case  of 
instruction  in  English  composition,  sharp,  since  any 
engineering  student  who  receives  one  type  of  instruc- 
tion will  receive  with  it  much  of  the  value  contained  in 
the  other  type.  And  the  two  types  are  not  by  any  means 
antagonistic.  Every  engineering  student  should  cer- 
tainly have  a  general  course  in  English  composition; 
and  most  engineering  students  are  given  such  a  course, 
usually  in  their  freshman  year.  But  experience  has 
shown  that  they  can  also  take  with  great  profit  specific 
instruction  in  the  composition  of  technical  papers. 
After  they  leave  college,  they  will  be  members  of  a  social 
organization,  and  the  liberalizing  value  of  the  general 

V 

3G580'1 


vi  PREFACE 

course  will  be  of  undoubted  service  to  them.  But  the 
bulk  of  whatever  writing  they  will  do  will  almost  cer- 
tainly be  of  a  professional  kind,  and  a  specific  course  in 
the  composition  of  technical  papers  will,  therefore,  also 
be  of  undoubted  service.  Any  professional  course  so 
specific  in  its  nature  that  its  value  to  the  student  rapidly 
evaporates  with  the  progress  of  engineering  science  may 
be  called  narrow  and  may  properly  be  ruled  from  the 
curriculum  of  the  engineering  college.  A  course  in  the 
composition  of  technical  papers  cannot,  however,  be 
narrow  and  comparatively  valueless,  inasmuch  as  the 
elements  of  which  it  is  composed  remain  constant  from 
year  to  year  with  their  value  to  the  student  unimpaired 
by  any  advance  in  engineering  knowledge.  A  course  in 
the  composition  of  technical  papers,  therefore,  although 
it  may  be  described  as  professional,  is  not  open  to  the 
danger  of  deterioration  in  value  which  threatens  many 
other  professional  courses. 

The  aims  and  methods  of  a  course  in  general  composi- 
tion for  engineering  students  have  been  set  forth  by  the 
present  writer  in  an  article  on  The  English  Department 
and  the  Professional  Schools  in  the  Bulletin  of  the  Society 
for  the  Promotion  of  Engineering  Education  for  October, 
191 6.  The  working  material  for  such  a  course  will  be 
found  in  Professor  Frank  Aydelotte's  English  and  Engi- 
neering (McGraw-Hill  Book  Company,  1917).  The 
Composition  of  Technical  Papers  is  designed  to  provide 
material  for  a  course  of  the  second  type.  The  book  is 
the  result  of  a  teaching  experience  of  several  years  at 
the  University  of  Wisconsin,  and  embodies  the  methods 
employed  there  in  a  one-semester,  three-hour  course 
elective  for  juniors  and  seniors  in  the  College  of  Engi- 
neering.    All  of  these  students  had  taken  the  regular 


PREFACE  vii 

freshman  English  course  in  their  first  year;  a  very  few 
had  also  had  other  university  courses  in  English  com- 
position. The  book  has  been  written,  however,  with 
regard  to  its  possible  use  in  a  first  course  in  college 
English.  It  has  one  aim  and  only  one, — to  teach  engi- 
neering students  to  write  better  technical  papers. 

Under  the  conditions  prevailing  at  Wisconsin  the  fol- 
lowing course  elements  seemed  to  produce  the  best 
results: 

1.  Two  weekly  class  meetings  for  informal  talks  on 
technical  writing,  analyses  and  study  of  specimens  from 
various  sources,  driU  in  paragraphs  and  sentences,  and 
other  class  exercises. 

2.  A  weekly  five-hundred  word  theme  of  the  type 
under  consideration  in  class. 

3.  A  regular  weekly  conference  of  at  least  fifteen  min- 
utes with  each  student. 

4.  A  semester  paper  of  from  two  to  three  thousand 
words  on  a  subject  of  especial  interest  to  the  student. 

At  the  class  meetings  students  were  expected  to  join 
freely  in  the  discussions,  and  were  encouraged  to  bring 
to  class  articles  from  technical  magazines  which  seemed 
worthy  of  especial  comment.  The  conferences  were 
substantially  private  lessons  based  on  the  weekly  themes. 
Students  usually  regarded  them  as  one  of  the  most 
serviceable  elements  in  the  course.  The  semester  paper 
was  the  pi^ce  de  resistance  of  the  theme  work;  it  was 
begun  early  in  the  semester  and  was  supposed  to  occupy 
the  student's  attention  throughout  the  course.  Many  of 
these  papers,  it  might  be  added,  were  subsequently 
published,  either  in  technical  magazines  or  as  separate 
pamphlets,  a  circumstance  which  greatly  stimulated  the 
interest  and  activity  of  the  students. 


Vlll 


PREFACE 


My  obligations  to  those  who  have  assisted  me  directly 
or  indirectly  in  the  preparation  of  the  volume  are  heavy. 
I  owe  much,  undoubtedly,  to  the  authors  of  the  numerous 
text-books  which  I  have  used  in  my  courses  in  composi- 
tion. My  most  conscious  obligation  in  this  direction 
is,  however,  to  the  almost  indispensable  Woolley's 
Handbook  of  Composition,  which  I  have  used  in  my  classes 
for  years,  and  upon  which  I  have  drawn  more  heavily 
perhaps  than  I  realize  for  my  chapter  on  the  sentence. 

A  number  of  busy  engineers  and  editors  of  technical 
magazines  have  given  me  -suggestions  for  the  develop- 
ment of  the  Wisconsin  course  in  technical  writing,  and 
I  wish  to  take  this  occasion  to  acknowledge  the  courtesy 
of  the  following  gentlemen:  Professor  Charles  F.  Scott, 
Mr.  Percy  H.  Thomas,  Mr.  Ralph  D.  Mershon,  Mr. 
S.  E.  Doane,  Mr.  Ralph  Beman,  Mr.  E.  J.  Edwards,  Mr. 
Frank  J.  Sprague,  Mr.  G.  A.  Wardlaw,  Mr.  Walter 
Jackson,  Mr.  W.  D.  Weaver,  Mr.  A.  L.  Rohrer,  Mr. 
Charles  B.  Going,  Mr.  C.  W.  Baker,  Mr.  Gano  Dunn, 
Mr.  B.  K.  Boyce,  and  Mr.  P.  W.  Kinney.  To  Mr. 
M.  C.  Rorty  of  the  American  Telephone  and  Telegraph 
Company  I  am  indebted  for  material  for  class  use  and 
for  many  helpful  suggestions,  and  to  my  brother,  Mr. 
H.  W.  Watt  of  the  Westche'ster  Lighting  Company, 
for  a  careful  criticism  of  the  manuscript  of  the  entire 
book  and  for  other  assistance. 

From  the  following  members  of  the  Engineering  College 
faculty  at  Wisconsin  I  receive.d  assistance  of  various 
kinds:  Professors  J.  W.  Watson,  C.  I.  Corp,  M.  C. 
Beebe,  L.  F.  Van  Hagan,  and  Mr.  F.  E.  Volk,  Librarian 
of  the  Engineering  Library. 

Messrs.  H.  A.  Burd,  S.  B.  Harkness,  and  H.  L.  Ride- 
nour  of  my  own  department  at  Wisconsin  read  parts  of 


PREFACE  ix 

my  manuscript  and  assisted  me  with  many  suggestions. 
To  Professor  F.  A.  Manchester  of  the  Enghsh  Depart- 
ment at  Wisconsin  I  owe  an  especial  debt;  he  read  the 
manuscript  of  the  first  part  of  the  book  with  his  usual 
patience  and  care,  and  corrected  my  judgment  and 
style  at  several  points.  Professor  W.  R.  Raymond  of 
the  Department  of  English  of  the  Iowa  State  College 
of  Agriculture  and  Mechanic  Arts  provided  me  with  a 
very  useful  list  of  technical  articles. 

Specific  acknowledgments  for  permission  to  reprint 
articles  or  parts  of  articles  have  been  made  at  the  ap- 
propriate places  within  the  book.  No  attempt  has  been 
made  always  to  indicate  the  source  of  short  paragraphs 
and  sentences  used  in  the  first  part  for  illustrations;  in 
many  cases  I  could  not  now  give  the  source. 

Finally,  I  owe  a  lasting  debt  to  my  students  in  the 
Wisconsin  course  in  technical  writing,  whose  interest 
in  the  work  was  a  continued  source  of  inspiration  to  me, 
and  from  whose  class  papers  I  have  drawn  freely  for 
illustrative  material. 


CONTENTS 

Preface v 

PART  I 

General  Principles  of  Expository  Writing 

CHAPTER  I 

Introduction 3 

The  Value  to  the  Practicing  Engineer  of  a  Training  in 
English  Composition — The  Types  of  Writing  with  which 
the  Engineer  is  Concerned. 

CHAPTER  II 

Fundamental  Problems  and  Suggestions 12 

Getting  the  Reader's  Point  of  View — Mechanical  Devices 
for  Assisting  the  Reader. 

CHAPTER  III 

Principles  which  Govern  the  Planning  and  Writing  of 

THE  Whole  Composition 20 

Selecting  the  Subject — Thinking  the  Subject  Over — 
Gathering  Information — The  Cardinal  Principles  of  Ex- 
position :  Unity,  Coherence,  and  Proportion — The  Title — 
The  Introduction — The  Conclusion — Style. 

CHAPTER  IV 

The  Paragraph 53 

Introduction — Paragraph  Division — Internal  Organiza- 
tion of  the  Paragraph. 

CHAPTER  V 

The  Sentence 77 

Introduction — Grammatical  Structure  of  the  Sentence — 

Punctuation:  The  Period,  Colon,  Semicolon,  and  Comma; 

xi 


xii  CONTENTS 

Question  Mark,  Dash,  Parenthesis  Marks,  Quotation 
Marks,  Apostrophe,  and  Hyphen — Good  and  Bad  Sen- 
tence Construction:  (i)  Sentence  Unity;  (2)  Coordination 
and  Subordination;  (3)  Parallelism;  (4)  Dangling  Modi- 
fiers; (5)  Weak  Reference;  (6)  Order  of  Parts;  (7)  Logical 
Agreement;  (8)  Incomplete  Statement;  (9)  Weak  Em- 
phasis— Defective  and  Weak  Sentences  for  Revision. 


PART  n 

Tjrpes  of  Technical  Exposition 

CHAPTER  VI 

Introduction  to  Part  II 143 

Technical  Description 

Principles 146 

Student  Themes 157 

Technical  Descriptions 

Electrical  World:  A  Convenient  Method  for  Replacing  Series 

Incandescent  Street  Lamps 168 

Mansfield  M  erriman :   The  Mechanical  Filter 1 70 

Electric  Railway  Journal:  Sand-drying  Plant  of  the  Metro- 
politan Street  Railway^  New  York 172 

Popular  Science  Monthly:  The  Electric  Burglar-alarm.  .    .  178 

George  C.  V.  Holmes:  The  Steam  Engine 186 

CHAPTER  VII 

Exposition  of  Processes 

Principles 198 

Student  Themes 204 

Expositions  of  Processes 

Charles  S.  Slichter:  Suggestions  on  the  Study  of  Mathe- 
matics  216 

Herbert  M.  Wilson:  Erecting  a  Tent 220 

Charles  W.  Domville-Fife:  Submarine  Construction  .    .    .   222 
George  Ellery  Hale:  The  Construction  of  a  Large  Reflecting 

Telescope 233 

Waltei  Sheldon  Towei:  Refining  Crude  Petroleum.    .    .    .241 


CONTENTS  xiii 
CHAPTER  VIII 

Exposition  of  Ideas 

Principles 255 

Student  Themes 267 

Expositions  of  Ideas 

John  F.  Robertson :  Electric  Heating  Devices 279 

John  W.  Alvord:  How  to  Use  the  Technical  Journal  .    .    .  281 
Engineering  Record:  Reading  Technical  Journals    .    .    .    .289 
Thomas  Henry  Huxley :  The  Method  of  Scientific  Investiga- 
tion   290 

Benjamin  Brooks:  The  Web-foot  Engineer 297 

P.   M.   Lincoln:   Inter  urban   Electric    Traction   Systems; 

Alternating  Current  vs.  Direct  Current 309 

JohnJ.  Carty:  Telephone  Service  in  America 317 

Charles  Buxton  Going:  The  Origin  of  the  Industrial  System  335 

CHAPTER  IX 

Reports 

Principles 348 

Student  Reports 366 

Professional  Reports 377 

CHAPTER  X 

Business  Letters 

Principles 392 

Student  Letters 409 

Professional  Letters 413 

IiTdex .421 


PART  I 

GENERAL  PRINCIPLES  OF 
EXPOSITORY  WRITING 


THE  COMPOSITION 

OF 

TECHNICAL  PAPERS 

CHAPTER  I 
INTRODUCTION 

The  Value  to  the  Practicing  Engineer  of  a  Train- 
ing IN  English  Composition 

"An  engineer  who  is  inarticulate,"  said  a  well-known 
New  York  engineer  in  speaking  of  the  value  to  members 
of  his  profession  of  a  thorough  knowledge  of  English, 
"is  quite  as  useless  as  one  who  is  professionally  incompe- 
tent." This  is  a  terse  and  vigorous  expression  of  a 
truth  which  all  experienced  engineers  recognize,  that  the 
man  who  has  not  the  power  to  give  his  ideas  clearly 
to  others,  the  man  whose  thoughts  are  locked  in  his 
brain  simply  because  he  has  not  the  ability  to  communi- 
cate them,  suffers  under  a  handicap  which  no  amount 
of  professional  knowledge  can  possibly  overcome.  The 
engineer  is  not  a  hermit  in  his  profession,  shut  off  from 
all  intercourse  with  others;  his  work  is  indissolubly 
bound  up  with  that  of  other  men,  and  he  finds  himself 
constantly  obliged  to  communicate  with  them.  The 
men  employed  by  an  electric-light  company,  from  the 
president  down  to  the  humblest  clerk,  are  individuals 
each  busied  with  his  own  particular  task,  to  be  sure, 
but  each  contributing  toward  a  common  end — the  suc- 
cess of  the  company.     And  because  of  this  common  aim 

3 


4       COMPOSITION  OF  TECHNICAL  PAPERS 

they  are  in  constant  communication  with  one  another, 
by  word  of  mouth,  by  letter,  by  written  report.  It 
can,  then,  be  readily  perceived  that  the  failure  on  the 
part  of  any  individual  employee  to  make  himself  clearly 
understood  by  other  employees  will  often  affect  very 
seriously  the  eflSciency  of  the  whole  machine.  An  in- 
complete, indefinite,  or  ambiguous  report  from  a  fore- 
man, for  example,  may  temporarily  delay  the  progress 
of  an  important  piece  of  work.  The  more  clearly  and 
effectively  the  communication  of  ideas  is  carried  on,  the 
more  efficiently  will  the  common  work  of  all  be  accom- 
plished. And  the  employee  who  is  best  able  to  express 
himself  clearly  and  exactly  is  the  one  who  will  stand  the 
best  chance,  other  things  being  equal,  of  advancement. 
The  young  engineer  who  writes  the  clearest,  most  accu- 
rate report,  the  foreman  who  can  explain  exactly  and  in 
a  few  words  just  what  he  wants  done,  are  the  men  whom 
the  superintendent  is  bound  to  notice.  There  is  more 
than  one  instance  on  record  of  promotions  which  have 
come  solely  as  the  result  of  the  ability  to  write  a  good 
report. 

But  it  is  not  only  in  his  daily  routine  that  the  engineer 
is  called  upon  to  express  himself  clearly;  it  often  happens 
that  he  has  an  even  harder  task  to  face  than  that  of 
making  himself  clear  to  his  fellow-workmen  and  to  his 
employers.  The  engineer  often  finds  himself  obliged 
to  make  clear  to  outsiders,  to  laymen,  certain  facts  or 
ideas  which  it  is  desirable  that  they  understand.  A 
city  engineer,  for  instance,  may  be  asked  to  explain  to 
the  city  council  the  nature  and  operation  of  a  sewage 
disposal  plant  which  they  have  been  considering.  It 
is  evident  that  he  must  make  an  explanation  which  will 
not  only  be  understood  by  a  municipal  engineer  but  which 


INTRODUCTION  5 

will  be  so  free  from  technical  details  and  language  that  the 
physicians,  lawyers,  and  business  men  on  the  council 
will  have  no  difficulty  in  following  it.  Similarly  a  mining 
engineer  may  find  himself  face  to  face  with  the  problem 
of  explaining  to  a  group  of  capitalists  the  nature  of  some 
project  in  which  they  are  interested;  and  in  this  case  his 
explanation  must  not  only  be  absolutely  clear,  but  it 
must  often  be  vigorous  and  persuasive.  If  he  does  not 
know  best  how  to  select,  arrange,  and  present  his  material, 
he  is  very  likely  to  confuse  and  tire  his  listeners  without 
enlightening  them. 

All  of  these  demands  upon  his  skill  in  speaking  and 
writing  will  come  to  every  engineer;  to  the  ambitious 
and  successful  engineer  will  almost  certainly  come  in 
addition  the  desire  to  put  his  ideas  into  "guid  black 
prent"  or  the  invitation  to  address  some  technical  or 
lay  association.  However  valuable  the  ideas  which  he 
may  wish  to  present  on  these  occasions  may  be,  his 
printed  article  or  his  address  is  not  likely  to  be  to  his 
credit  if  he  is  incoherent  or  weak.  The  editors  of 
technical  journals  do  not  care  to  give  up  the  valuable 
inches  in  their  magazines  to  men  who  do  not  know  how 
to  say  what  they  wish  to  say;  and  societies  soon  cease 
to  invite  to  their  platforms  men  who  ramble,  stammer, 
and  confuse  them  with  illogical  and  unentertaining 
presentations.  On  the  other  hand,  the  engineer  who  is 
skillful  and  clear  and  easy  in  speech  and  written  expres- 
sion never  knows  the  depressing  feeling  of  inability  which 
comes  to  the  untrained  man  who  tries  to  express  him- 
self, and  the  more  depressing  sense  of  failure  which  comes 
to  such  a  man  at  the  realization  that  his  readers  can  not 
understand  him  or  his  audience  follow  him. 

There  is  one  further  reason  for  the  engineer's  consider- 


6       COMPOSITION  OF  TECHNICAL  PAPERS 

ing  as  important  the  ability  to  express  himself  correctly; 
it  is,  that  incorrect  expression  marks  him  at  once  as 
crude  and  uncultivated.  To  be  able  to  communicate 
with  one's  colleagues  and  to  be  able  to  explain  to  inter- 
ested outsiders  the  nature  of  one's  work  are  professional 
accompHshments.  But  the  engineer  is  more  than  a 
professional  being;  he  is  a  social  being  as  well.  And,  it 
might  be  said  in  passing,  few  persons  realize  how  closely 
their  professional  interests  are  bound  up  with  their  social 
accomplishments.  The  engineer  who  uses  bad  grammar 
and  loose,  incoherent  expressions  in  his  social  communi- 
cations, spoken  or  written,  with  men  of  other  professions, 
stamps  himself  at  once  as  unpolished,  and  often  shuts 
himself  out  from  a  circle  of  acquaintanceships  which  would 
broaden  his  interests  and  freshen  his  ideals.  He  may 
acquire  money  in  spite  of  this  handicap,  but  he  is  not 
likely  to  attain  a  high  position  in  his  profession  or  to  win 
the  respect  of  his  associates. 

The  inability  of  the  engineer,  then,  to  communicate 
his  ideas  clearly,  concisely,  and  accurately  will  not  only 
handicap  him  in  many  ways  but  may  even  affect  detri- 
mentally the  work  of  others  with  whom  he  is  associated. 
His  ability,  on  the  other  hand,  to  speak  and  write  with 
coherence  and  force  is  a  professional  and  social  ac- 
complishment the  value  of  which  no  thinking  engineer 
will  deny. 

The  Types  of  Writing  with  which  the  Engineer 
IS  Concerned 

The  principles  governing  composition  were  worked 
out  through  a  long  process  of  experimentation  in  which 
obviously  good  and  obviously  bad  pieces  of  writing  were 
analyzed  to  determine  what  made  them  good  in  the  one 


INTRODUCTION  7 

case  and  bad  in  the  other.  If  an  explanation  seemed 
clear  and  vigorous,  the  rhetorician  asked,  "What  has 
the  writer  done  to  give  it  these  desirable  qualities?" 
If  it  was,  on  the  other  hand,  obscure  and  difficult  to 
follow,  the  question  asked  was,  "What  has  the  writer 
failed  to  do  or  what  wrong  thing  has  he  done  so  to  confuse 
his  reader?"  By  this  and  similar  processes  of  analysis 
it  was  determined  that  there  are  certain  principles  and 
tricks  of  the  trade  of  writing,  an  allegiance  to  which  pro- 
duces in  composition  such  desirable  qualities  as  unity 
of  effect,  clearness,  ease,  and  vigor,  and  the  violation  of 
which  tends  to  produce  the  opposite  qualities.  Hence 
come  books  of  rhetoric  which  aim  to  teach  men  to  write 
by  setting  forth  and  illustrating  the  principles  thus  dis- 
covered. Many  of  these  principles  are  little  more  than 
the  sorting  out  and  labeling  of  what  to  a  man  of  native 
intelligence  seems  obviously  the  common-sense  thing  to 
do,  and  the  "born  writer"  or  the  man  who  has  by  exten- 
sive reading  of  the  best  in  literature  acquired  a  sense  for 
what  is  correct  in  writing  may  feel  little  need  for  the  cold 
principles.  Unfortunately,  however,  few  men  are  born 
writers,  and  not  many  have  the  desire  or  opportunity 
to  acquire  correct  form  by  the  uncertain  process  of  exten- 
sive reading;  to  the  average  man,  therefore,  the  so-called 
"rhetorical  principles"  provide  an  extremely  valuable 
short-cut  to  correct  writing.  It  should,  of  course,  be 
evident  that  a  mere  study  of  the  pure  theory  of  writing, 
without  analysis  of  good  examples  and  without  prac- 
tice in  composition,  is  of  no  more  value  than  the  reading 
of  a  treatise  on  swimming  without  accompanying  ob- 
servation and  practice.  But  properly  assimilated  and 
appUed  the  principles  of  good  writing  may  be  made  very 
serviceable. 


8      COMPOSITION  OF  TECHNICAL  PAPERS 

Any  "course"  in  composition  consists  of  the  study  of 
the  principles  of  clear  thinking  and  correct  and  effective 
writing,  and,  in  addition,  the  supervised  application  of 
these  principles  in  written  compositions,  or  "  themes, " 
of  varying  lengths  and  varieties.  "The  following  prac- 
tices," says  the  teacher  at  the  beginning  of  such  a  course, 
"have  resulted  in  the  production  of  good  writing;  if  you 
apply  them  with  a  reasonable  amount  of  skill,  and  if  you 
do  not  violate  what  modern,  national,  and  reputable 
writers  have  declared  to  be  good  usage  in  other  respects, 
what  you  write  should  possess  the  fundamental  qualities 
which  will  make  it  clear  and  pleasing  to  your  reader." 
Many  of  these  practices  are  so  fundamental  that  they 
apply  to  the  writing  of  the  engineer  as  much  as  to  that  of 
the  literary  man.  The  engineer  is  concerned,  however, 
with  certain  of  these  principles  more  than  with  others, 
with  those  that  arise  from  the  particular  kinds  of  writing 
in  which  he  is  professionally  interested. 

Writing  is  ordinarily  divided  into  four  types:  narration, 
description,  exposition,  and  argumentation.  This  divi- 
sion is,  of  course,  a  purely  artificial  one,  made  for  pur- 
poses of  analysis  and  study;  writers  do  not  usually  say 
as  they  pick  up  their  pens,  "Now  I  am  going  to  write 
narration,"  or,  "This  composition  will  be  a  specimen 
of  argumentation."  The  distinction  between  the  forms 
is  not  always  easy  to  make.  Poe's  Gold-Bug  is  obviously 
narrative,  and  a  book  on  alternating  currents  is  just  as 
obviously  expository;  but  The  Story  of  a  Piece  of  Coal  and 
My  Trip  to  a  Copper-Mine  are  narrative  in  form  while 
expository  in  substance.  It  is  safest,  on  the  whole,  to 
determine  the  type  not  from  the  title  and  form  but  from 
the  content  and  evident  aim  of  the  writer.  If  his  attempt 
is  to  entertain  the  reader  in  a  succession  of  events  told  for 


INTRODUCTION  9 

their  own  sake  or  because  of  their  artistic  entanglement, 
he  is  writing  narration.  If  he  is  attempting  to  reproduce 
in  the  mind  of  the  reader  an  image,  feeUng,  or  impression 
which  he  has  received,  he  is  writing  description,  \ 
Exposition,  or  explanation,  deals  with  facts  or  ideas;  the 
writer's  purpose  here  is  usually  didactic — ^he  aims  to  ' 
enlighten  his  reader,  A rgumentation  is  exposition  charged 
with  persuasion;  the  facts  become  proofs,  and  the  • 
writer  attempts  not  only  to  enlighten  the  reader  but  also 
to  convert  him  to  his  own  way  of  thinking.  Examined 
in  the  light  of  these  brief  definitions  My  Trip  to  a  Copper- 
Mine  is  seen  to  be  really  exposition,  since  the  writer's 
aim  is  clearly  didactic.  Similarly  the  "story"  part  of 
The  Story  of  a  Piece  of  Coal  appears  merely  as  the  season- 
ing of  the  explanation — the  sugar  coating  on  the  pill. 
The  professional  writing  of  an  engineer,  judged  from 
the  content  and  from  the  aim  of  the  writer,  is  all  exposi- 
tion or  argumentation.  This  statement  does  not  mean 
that  bits  of  pure  description  or  even  of  narration  may 
not  occasionally  enter  in;  it  does  mean,  however,  that 
the  attitude  of  the  engineer  in  all  his  professional  writing 
is  that  of  an  expositor  or  of  a  propagandist,  of  an  indi- 
vidual possessed  of  certain  information  which  it  is  his 
aim  to  pass  on  to  his  reader,  or  of  a  man  making  converts 
to  his  way  of  thinking.  Where  he  is  not  arguing,  the 
engineer  is  always  enlightening  or  explaining.  An  ex- 
amination of  the  kinds  of  writing  with  which  the  engineer 
is  concerned  reveals  at  once  the  expository  basis  of  it 
all.  The  explanation  of  a  process,  for  example,  whether 
it  be  the  explanation  of  a  method  of  analysis  or  of  a 
process  of  manufacture,  is,  like  The  Story  of  a  Piece  of 
Coal,  narrative  only  in  form.  The  arrangement  of 
material  is  almost  certain  to  be  chronological,  but  the 


lo     COMPOSITION  OF  TECHNICAL  PAPERS 

content  is  that,  not  of  a  narration,  but  of  an  exposition, 
and  the  aim  of  the  writer  is  clearly  to  enlighten  his  reader, 
not  merely  to  entertain  him.  Similarly  the  engineer 
may  describe  a  new  hydro-electric  plant,  but  here  he  is 
not  by  any  means  attempting  merely  to  create  in  the  mind 
of  the  reader  a  picture  of  the  plant;  this  may  be  a 
necessary  subordinate  part  of  his  object,  but  his  chief 
concern  is  in  making  clear  certain  details  of  construction 
and  operation;  he  is,  in  other  words,  explaining.  In 
this  case  and  in  the  case  of  the  explanation  of  a  process 
the  engineer's  attitude  of  mind  toward  his  reader  is  quite 
different. from  that  of  the  writer  of  artistic  description 
and  of  narration.  Other  kinds  of  engineering  writing, 
definitions  and  abstract  expositions,  such  as  explanations, 
for  example,  of  physical  laws  and  the  setting  forth  of 
theories,  belong  clearly  within  the  field  of  exposition. 
Reports  and  letters  are  special  forms  of  writing  which  con- 
tain certainly  more  expository  than  other  elements. 
Arguments,  as  has  been  said,  are  explanations  charged 
with  persuasion.  A  study  of  argumentation  has  its 
basis  in  an  understanding  of  the  principles  of  expository 
writing;  to  this  is  added  a  study  of  the  principles  of 
persuasion  and  conviction. 

Since  the  professional  writing  of  the  engineer,  there- 
fore, is  practically  all  expository  or  explanatory,  the 
engineer  is  concerned  in  his  study  of  the  laws  of  good 
writing  mainly  with  the  principles  of  exposition  writing. 
He  must  know  the  fundamental  difficulties  which  beset 
the  writer  of  expositions,  and  how  to  avoid  them;  he 
must  learn  the  laws  of  good  general  organization  and  of 
the  minor  compositional  units,  the  paragraph  and  the 
sentence;  and  he  must,  finally,  devote  especial  attention 
to  the  forms  of  expository  writing  with  which  he  is  pro- 


INTRODUCTION  ii 

fessionally  concerned,  explanations  of  processes,  technical 
descriptions,  reports,  and  letters.  All  these  parts  of  his 
study  will  be  taken  up  here  in  regular  order.  First,  of 
course,  comes  a  consideration  of  some  of  the  fundamental 
and  initial  difficulties  which  he  will  encounter,  and 
suggestions  for  avoiding  and  correcting  them. 


CHAPTER  II 
FUNDAMENTAL  PROBLEMS  AND  SUGGESTIONS 

Getting    the    Reader's   Point    of   View 

Writing  is  a  process  of  transferring  to  others  by  means 
of  visible  symbols  ideas  which  exist  originally  in  our  own 
minds.  It  is  one  means  of  expression,  of  transmission 
of  thought.  Speech,  which  is  another  means  of  expres- 
sion, is  at  best  an  imperfect  medium  for  conveying  ideas; 
and  writing,  deficient  in  those  auxiliary  devices  of 
intonation,  facial  expression,  and  gesticulation  which 
speech  possesses,  is  even  more  imperfect.  The  ideas  of 
the  average  man  are  very  likely  to  be  badly  jumbled; 
his  brain  has  a  curiously  perverse  trick  of  skipping  from 
one  detail  of  a  subject  to  another  in  a  most  irregular 
manner,  and  only  the  most  strenuous  efforts  at  mental 
concentration  will  bring  order  out  of  chaos.  But  even 
when  the  writer  has  finally  succeeded  in  getting  his  mind 
to  thinking  clearly  and  connectedly,  he  has  made  only 
the  initial  step;  there  still  remains  the  writing,  the  trans- 
lation of  the  ideas  into  the  written  symbols  which  are 
to  stand  for  them.  And  here  a  thousand  pitfalls  yawn 
for  him.  He  may  carelessly  separate  ideas  which  belong 
together;  he  may  over-emphasize  an  unimportant  idea 
by  giving  it  too  important  a  form  or  too  emphatic  a 
position,  or  he  may  under-emphasize  a  really  important 
thought  by  subordinating  it  in  construction  or  in  posi- 
tion; he  may  select  a  word  which  does  not  at  all  convey 


FUNDAMENTAL  PROBLEMS  13 

the  idea  which  he  intended  it  to  carry;  he  may  even  by 
an  incorrect  construction  obscure  the  meaning  of  his 
idea  entirely  or  in  some  cases  give  a  thought  exactly  the 
opposite  of  that  which  he  had  in  mind.  A  knowledge 
of  the  errors  in  expression  which  result  in  the  reader's 
misunderstanding,  and  then  constant  vigilance  in  guard- 
ing against  these  errors  is  the  price  of  clear,  effective 
writing. 

The  most  fundamental  cause  of  failure  in  writing  is  the 
inability  of  the  writer  to  realize  the  absolute  dependence 
of  the  reader  for  his  understanding  of  the  ideas  to  be 
conveyed  upon  the  written  expression  of  those  ideas. 
Most  writers  are  too  self-conscious;  they  forget  that  they 
are  writing  not  for  themselves  but  for  other  persons.  They 
forget  that  if  the  reader  knew  as  much  about  the  subject 
as  they  do,  they  need  not  write  at  all.  It  may  happen,  to 
be  sure,  that  their  reader  is  already  familiar  with  certain 
of  the  ideas  with  which  they  are  dealing.  Essentially, 
however,  the  relation  of  writer  and  reader  is  this:  the 
writer  has  in  his  mind  certain  conceptions,  whether  they 
concern  facts,  concrete  mental  images,  or  abstract  ideas, 
which  the  reader  is  not  in  possession  of;  it  is  his  task  to 
transmit  these  conceptions  as  accurately  as  possible. 
The  writer  is  manifestly  better  situated  than  is  the  reader, 
for  after  he  has  completed  his  paper,  he  possesses  not 
only  the  written  expression  of  the  ideas  which  he  gives 
the  reader — his  manuscript — but  he  has  also  the  original 
ideas  as  they  exist  in  his  mind;  whereas  the  reader  must 
reach  the  mind  of  the  writer  solely  through  the  imperfect 
medium  of  the  author's  manuscript.  Herein  Ues'  the 
writer's  difficulty;  he  reads  his  paper  over  before  giving 
it  to  the  reader  and  unconsciously  corrects  from  the  full- 
ness of  his  own  knowledge  those  gaps  and  inaccuracies 


14    COMPOSITION  OF  TECHNICAL  PAPERS 

in  expression  which  cause  the  reader  to  scratch  his  head 
and  ask,  "Now  what  does  he  mean?"  In  other  words, 
the  writer  is  handicapped  by  his  very  knowledge  of  his 
subject;  he  cannot  understand  why  what  is  perfectly 
clear  to  him  in  his  paper  should  not  also  be  perfectly 
clear  to  his  reader. 

It  should,  accordingly,  be  the  aim  of  the  writer  to 
approach  as  nearly  as  possible  the  point  of  view  of  his 
reader.  In  fact,  the  more  closely  the  author  can  identify 
himself  with  the  reader,  the  more  clearly  will  he  write. 
Very  careful  writers  usually  submit  their  manuscripts 
to  friends  or  to  paid  readers  before  sending  them  to  the 
publishers,  because  they  realize  that  expressions  which 
seem  intelligible  to  them  may  not  seem  so  at  all  to  others. 
This  method  of  testing  out  the  clearness  of  what  has  been 
written  is  not,  of  course,  always  practicable;  too  often 
the  only  reader  is  the  one  for  whom  the  paper  is  intended. 
But  within  certain  limits  the  writer  can  be  his  own  pre- 
liminary reader.  This  he  can  accomplish  by  training 
himself  to  take  a  mercilessly  critical  attitude  toward 
his  writing.  He  can  not  make  any  expression  absolutely 
fool-proof,  but  he  can  with  care  so  write  that  there  is 
very  little  danger  of  his  being  misunderstood.  Such 
a  principle  of  workmanship  often  means  rewriting  and 
painstaking  correction;  but  this  much  care  is  due  the 
reader.  If  Huxley,  a  master  of  prose  style,  could  afford 
to  rewrite  one  of  his  lectures  seven  times,  writers  less 
skilled  can  hardly  afford  to  impose  upon  their  readers 
hasty,  unrevised  compositions  of  any  sort.  One  very 
practical  means  which  the  writer  may  adopt  of  discon- 
necting himself  from  his  original  thoughts  and  of  thereby 
approaching  the  point  of  view  of  his  reader  is  that  of 
putting  his  composition  aside  for  a  period  of  time  until 


FUNDAMENTAL  PROBLEMS  15 

what  he  intended  to  say  has  become  less  fresh  in  his 
mind;  then  he  will  be  better  able  to  judge  of  the  clearness 
of  what  he  actually  has  said  and  to  correct  his  sins  of 
omission  and  of  commission.  This  process  is,  of  course, 
not  always  possible;  wherever  it  is  done,  however,  it 
never  fails  to  result  in  a  clearer  piece  of  writing. 

There  is  one  specific  part  of  this  problem  of  identify- 
ing oneself  with  the  reader  which  needs  especial  emphasis. 
The  writer  must  be  very  careful  to  use  language  which  the 
reader  will  understand.  Any  technical  writer,  whether 
he  be  engineer,  lawyer,  or  physician,  is  likely,  often  with- 
out realizing  it,  to  use  a  professional  jargon  which  only 
the  initiated  can  understand.  The  engineer  should 
remember  that  he  is  not  always  writing  for  engineers. 
When  he  is  composing  a  report  for  his  superior,  or  when 
he  is  addressing  an  engineering  society,  he  will  naturally 
make  use  of  the  technical  language  of  his  profession; 
when,  however,  he  is  writing  a  general  report  for  a  com- 
mittee of  capitaUsts,  or  when  he  is  addressing  a  city 
council,  he  must  use  a  language  which  they  will  under- 
stand. Many  professional  men  take  a  very  natural 
pride  in  appearing  learned  in  their  profession;  the  most 
successful  professional  men,  however,  recognize  the  fact 
that  simplicity  of  language  and  phrasing  is  more  to  be 
desired  than  a  glossing  of  technical  expressions.  One 
of  the  best  known  hydraulic  engineers  in  America,  who 
recognizes  this  principle  fully,  recently  wrote  in  the 
Letter  of  Transmittal  accompanying  a  report  addressed 
to  an  exploiting  committee: 

"I  have,  as  far  as  possible,  endeavored  to  avoid  technicali- 
ties and  to  make  my  meaning  so  plain  that  my  statements 
can  be  understood  and  my  reasoning  followed  by  any  business 
man,  even  though  unfamiliar  with  water  power.     For  this 


1 6     COMPOSITION  OF  TECHNICAL  PAPERS 

reason  I  have  included  in  the  appendix  various  information  of 
technical  matters  and  further  discussions  of  important 
matters  which,  if  discussed  in  the  body  of  the  report,  would 
have  been  objectionable."^ 

This  same  engineer  explained  the  somewhat  intricate 
operations  of  a  hydro-electric  plant  and  certain  problems 
connected  with  it  so  clearly  that  probably  not  one  of  his 
audience  of  business  men,  teachers,  and  lawyers  failed 
to  understand  him.  He  did  it  simply  by  avoiding  tech- 
nical terms  and  technical  details  as  far  as  possible  and  by 
using  a  great  many  concrete  examples  and  comparisons 
drawn  from  the  common  experience  of  all  of  his  listeners. 
Huxley  could,  before  an  audience  of  his  scientific  associ- 
ates, make  free  use  of  scientific  words  and  details  which 
would  drive  the  average  university  graduate  to  despera- 
tion; he  could,  on  the  other  hand,  make  the  most  difficult 
and  abstract  scientific  matters  perfectly  clear  to  an  audi- 
ence of  London  laboring  men  simply  by  keeping  con- 
stantly in  mind  the  limits  of  their  scientific  attainments 
and  by  meeting  them  on  the  ground  of  common 
experience. 

The  extent  to  which  language  and  manner  of  presenta- 
tion should  be  adapted  to  the  reader  must,  of  course,  be 
predetermined  in  every  case.  A  report  addressed  to  a 
veteran  engineer  will  obviously  be  different  from  the 
same  report  addressed  to  a  business  man.  For  that 
uncertain  individual,  the  general  reader,  it  is  safest  to 
avoid  technical  expressions  as  far  as  possible;  the  reader 
can  forgive  the  writer  who  is  occasionally  too  simple  in 
his  explanation  but  he  can  not  forgive  the  writer  who  is 
unintelligible. 

1  Daniel  W.  Mead:  Report  on  the  Water  Power  of  the  Rock  River,  Jan.  i. 


FUNDAMENTAL  PROBLEMS  17 

To  avoid  technical  language  and  to  write  simply  is  not 
in  the  least  to  lower  one's  professional  dignity.  In  fact, 
to  be  able  to  make  a  technical  matter  clear  to  a  "man  who 
has  no  knowledge  of  one's  profession  requires  skill  of  a 
very  high  order.  The  writer  who  can  do  this  successfully 
has  no  difficulty  in  being  technical  enough  when  occasion 
demands  it. 

Mechanical  Devices  for  Assisting  the  Reader 

Psychologists  assert  that  eighty-five  per  cent,  of  a 
man's  information  comes  through  his  eyes,  and  there  is 
an  old  saying  that  ''you  can  get  more  knowledge  into  a 
man's  head  through  his  eyes  with  a  teaspoon  than  you 
can  get  through  his  ears  with  a  scoop-shovel."  The  mind 
of  every  reader  yearns  for  a  graphic  representation  of  the 
ideas  which  he  is  reading,  and  it  is  a  part  of  the  duty  of 
the  writer  of  technical  articles  to  satisfy  this  desire. 
Accordingly,  any  use  of  diagrams,  drawings  and  illus- 
trations, curves  and  statistical  tables  is  not  only  perfectly 
legitimate  but  often  absolutely  necessary  to  a  complete 
and  accurate  understanding  of  a  difficult  exposition.  A 
single  sketch,  carefully  executed,  will  often  give  the 
reader  more  information  than  pages  of  written  explana- 
tion. On  the  other  hand,  it  is  quite  possible  for  a  care- 
less, inaccurate  drawing  to  add  to  the  confusion  which 
comes  from  an  incoherent  explanation.  Attention  to  a 
few  simple  principles  in  the  use  of  these  auxiliary  devices 
will,  therefore,  save  the  reader  much  annoyance. 

All  diagrams  and  sketches  should  be  neatly  and  care- 
fully done;  a  slovenly,  careless  drawing  detracts  from  the 
appearance  of  the  manuscript  and  disgusts  the  reader 
even  where  it  does  not  mislead  him.    The  drawing  should 


i8     COMPOSITION  OF  TECHNICAL  PAPERS 

be  set  off  distinctly  from  the  text;  if  a  liberal  white  margin 
does  not  surround  it,  it  fails  to  stand  out  and  is,  therefore, 
difficult  to  examine.  Parts  of  the  drawing  referred  to  in 
the  text  should  be  carefully  lettered;  all  such  letters 
should  be  conspicuously  and  unmistakably  placed  so 
that  the  reader  does  not  have  to  search  for  them  and  so 
that  he  can  readily  connect  each  letter  with  the  part  to 
which  it  refers.  Where  there  are  several  drawings  in  a 
manuscript,  it  is  often  advisable  to  give  a  title  to  each  one 
in  addition  to  its  number.  The  reader  is  often  helped, 
moreover,  by  finding  beneath  each  drawing  in  which 
there  are  several  parts  referred  to  by  letters,  a  table 
giving  the  letters  alphabetically  and  the  names  of  parts 
to  which  the  letters  refer ;  this  should  be  done  in  addition 
to  giving  text  references.  Economy  in  the  use  of  dia- 
grams and  drawings  is  desirable;  for  example,  in  a  descrip- 
tion of  a  slide-rule  it  is  better  to  show  in  a  single  sketch 
the  rule  and  the  inserted  slide  projecting  than  to  use  two 
separate  sketches,  one  for  each  part. 

Many  of  the  suggestions  given  for  sketches  apply  also 
to  curves  and  tables.  Accuracy  and  care  are  very  essen- 
tial. Visual  devices  to  assist  the  reader  may  also  be 
used  here;  for  example,  in  the  case  of  long  statistical 
tables  occasional  vertical  and  horizontal  lines  drawn 
between  rows  of  figures  will  break  up  the  mass  and  assist 
the  eye  to  read  the  numbers.  Two  or  more  tables  or 
curves  used  in  comparisons  should,  where  possible,  be 
put  side  by  side  so  that  the  comparison  which  the  reader 
is  expected  to  make  can  be  carried  on  readily. 

In  addition  to  helping  his  reader  by  using  sketches, 
curves,  and  tables,  the  writer  of  technical  articles  may 
make  use  of  certain  mechanical  devices  in  his  manu- 
script.   The  listing  and  numbering  in  the  introduction  of 


FUNDAMENTAL  PROBLEMS  19 

the  parts  of  a  subject  to  be  taken  up  and  the  correspond- 
ing naming  and  numbering  of  each  division  as  it  is  be- 
gun in  the  body  is  a  very  useful  device  for  assisting  the 
reader  to  follow  the  plan  of  an  article.  In  articles  of 
some  length,  moreover,  the  newspaper  practice  of  insert- 
ing occasional  sub-titles  is  often  very  helpful.  When 
these  are  put  in  the  margins,  they  become  to  the  article 
what  a  thumb-index  is  to  a  dictionary;  they  guide  the 
reader  in  his  perusal  of  the  article  and  enable  the  busy 
man  who  is  looking  for  only  a  part  of  the  paper  to  find 
that  part  immediately.  All  such  devices  as  these, 
where  they  aim  really  to  assist  the  busy  reader  and  are 
not  mere  useless  flourishes,  are  perfectly  legitimate  and 
dignified. 


CHAPTER  III 

PRINCIPLES   WHICH   GOVERN   THE  PLANNING 
AND  WRITING  OF  THE  WHOLE  COMPOSITION 

Selecting  the  Subject 

The  problem  of  knowing  what  to  write  about  does  not 
ordinarily  trouble  the  engineer,  for  usually  his  subject  is 
either  assigned  to  him  or  suggests  itself.  In  the  case  of 
reports  the  writer  always  has  a  more  or  less  definite 
problem  set  for  him.  Where  he  is  more  ambitious  than 
the  average  engineer,  who  writes  nothing  but  reports 
and  letters,  and  feels  called  upon  to  pubHsh  in  the 
technical  press  some  of  his  ideas  or  the  results  of  some 
of  his  investigations  or  observations,  he  usually  waits 
until  a  subject  which  is  worth  while  suggests  itself.  The 
man  who  wants  to  print  something,  it  does  not  matter 
what,  merely  for  the  sake  of  advertising  himself  is  the 
only  writer  who  has  to  cast  about  for  a  subject.  The 
engineer,  on  the  other  hand,  who  feels  seriously  the  duty 
of  assisting  his  brother  engineers  in  the  solution  of  the 
problems  which  daily  confront  them  does  not  bombard 
the  editors  of  technical  magazines  with  commonplace 
descriptions  of  perfectly  commonplace  engineering  con- 
structions or  with  vain  repetitions  of  ideas  as  ancient  as 
Euclid;  he  waits  until  he  has  some  idea  which  he  con- 
scientiously believes  to  be  fresh  and  likely  to  be  inter- 
esting or  until  he  has  met  a  new  problem  or  worked  out 
a  new  solution  of  an  old  one.     Such  subjects,  the  only 


THE  WHOLE  COMPOSITION  21 

ones  really  worth  accepting,  do  not  have  to  be  sought 
for;  they  come  to  the  writer  with  the  conviction  that 
they  are  certain  to  interest  his  readers. 

Thinking  the  Subject  Over 

Once  the  suljject  has  been  thus  assigned  or  suggested, 
the  writer  may  begin  work  at  it  immediately  by  turning 
it  over  and  over  in  his  head  as  a  lawyer  would  revolve 
in  his  mind  one  of  his  cases  and  as  a  teacher  would  think 
over  the  problems  connected  with  the  teaching  of  a 
difficult  lesson.  The  writer  can  not,  by  taking  thought 
in  this  way,  add  anything  to  his  actual  knowledge  of 
the  subject;  he  can,  however,  by  this  process  clarify 
what  ideas  he  may  have  and  decide  many  questions  of 
arrangement  and  presentation  of  material.  No  writer 
should  attempt  to  do  any  writing  whatever  until  he  has 
given  his  subject  this  chance  to  grow  into  some  definite 
substance  and  form.  In  composition  it  is  the  brain 
which  is  the  creative  instrument,  not  the  fingers.  While 
he  is  thinking  his  subject  over,  he  should  ask  himself 
repeatedly,  "Now  what  is  the  best  division  of  this 
material?'*  "Which  of  these  points  should  come  first?" 
"Where  can  I  get  an  illustration  of  this  idea?"  "Will 
my  reader  understand  this?"  and  similar  questions  which 
aim  to  stimulate  his  thinking  and  to  assist  him  in  getting 
the  point  of  view  of  his  reader. 

Gathering  Information 

While  this  process  of  revolving  the  subject  in  his  mind 
is  going  on,  he  will,  of  course,  be  adding,  if  necessary, 
to  his  stock  of  information  on  the  subject.     Such  infor- 


2  2     COMPOSITION  OF  TECHNICAL  PAPERS 

mation  may  come  from  a  reading  of  technical  books  or 
journals,  from  actual  inspections  and  investigations,  from 
interviews  with  authorities,  or  sometimes,  in  the  case  of 
an  exposition  setting  forth  an  opinion,  from  a  simple 
gathering  together  of  the  experiences  of  the  writer  and 
of  others  to  prove  a  theory  or  belief.  He  should  be  in  no 
hurry  to  get  to  the  actual  writing.  He  should  think  over 
his  material  for  as  long  a  time  as  possible;  then,  when  he 
actually  does  begin  the  transference  of  his  ideas  to  paper, 
he  will  be  full  of  his  subject  and  will  write  with  more 
spontaneity  and  flow  and  ease  than  he  would  otherwise. 
When  he  finally  begins  the  process  of  actual  composition, 
he  comes  face  to  face  with  the  problems  of  writing,  or 
presenting  his  ideas. 

The    Cardinal    Principles    of    Exposition:    Unity, 
Coherence,  and  Proportion 

Analyses  of  all  but  mere  one-paragraph  compositions 
show  them  to  be  made  up  of  words  which  are  grouped 
into  sentences,  sentences  which  are  grouped  into  para- 
graphs, and  paragraphs  which  are  grouped  together  to 
form  the  whole  composition.  Now  the  writer  who  con- 
scientiously desires  to  give  his  readers  the  very  best 
expression  of  his  ideas  must  attend  constantly  to  all  of 
these  divisions.  If  his  paragraphs  are  loosely  con- 
structed, the  fact  that  the  general  organization  of  the 
paper  is  good  will  not  excuse  him;  if  his  sentences  are 
unintelligible,  his  readers  will  not  forgive  him  because 
his  paragraph  divisions  seem  correctly  made.  Theo- 
retically, then,  it  would  be  best  for  the  student  who 
combines  study  of  theory  with  practice  in  writing  if  he 
could  learn  at  once  all  the  principles  relating  to   the 


THE  WHOLE  COMPOSITION  23 

whole  composition,  the  paragraph,  and  the  sentence, 
since  in  any  composition  ^hich  he  writes  he  may  violate 
any  of  them;  practically,  however,  the  principles  which 
govern  each  division  must  be  taken  up  separately.  We 
shall,  accordingly,  take  up  first  the  most  essential  prin- 
ciples of  effective  exposition  in  so  far  as  they  affect  the 
whole  composition. 

The  first  principle  with  which  the  writer  is  concerned 
is  that  of  Unity.  Unity  means  oneness  of  composition; 
to  secure  it  the  writer  must  stick  rigidly  to  his  subject 
and  avoid  all  temptation  to  digress.  Although  this  may 
seem  to  be  a  simple  practice  to  follow,  it  is  by  no  means 
easy  at  all  times  to  define  rigidly  the  limits  of  the  subject 
with  which  one  is  dealing  and  then  to  avoid  breaking 
over  the  line  which  has  been  set.  There  are  constant 
temptations  to  drift  off  into  details  which  have  only  the 
remotest  connection  with  the  subject,  and  before  the 
writer  realizes  that  he  has  been  wandering,  he  is  far 
afield.  Even  clear-headed  lecturers  sometimes  digress 
in  this  fashion  until  their  listeners  nudge  one  another  and 
ask,  "Now  what  does  he  think  he  is  talking  about 
anyway?" 

To  secure  unity  it  is  necessary  for  the  writer  first,  to 
form  a  very  definite  idea  of  the  scope  of  his  subject,  and, 
second,  to  guard  himself  constantly  lest  he  go  outside  the 
limits  which  he  has  set.  In  some  forms  of  engineering 
writing  these  precautions  are  not  very  difficult  to  observe. 
When  one  is  writing  a  descriptive-explanation  of  a 
machine,  for  example,  there  is  not  much  danger  of  his 
writing  about  anything  but  the  machine,  although  even 
here  he  may  set  out  to  write  a  mere  description  and 
find  himself  talking  about  the  advantages  of  the  type  of 
machine  under  consideration  over  other  types.     Again, 


24    COMPOSITION  OF  TECHNICAL  PAPERS 

an  explanation  of  a  process  is  easy  to  unify  if  one  is  care- 
ful to  stick  to  a  simple  narrative  account  of  the  different 
stages  in  the  process.  The  principle  of  unity  is  most 
likely  to  be  violated  when  the  subject  does  not  suggest 
at  once  its  own  limitations,  in  which  it  is  necessary, 
in  other  words,  for  the  writer  to  set  his  own  boundaries. 
Such  subjects  as  explanations  of  abstract  theories,  com- 
parisons of  different  methods  of  manufacture,  and  many 
forms  of  reports  are  much  more  difficult  to  unify  than  are 
descriptive-expositions  of  machines  or  explanations  of 
processes.  In  all  cases  where  the  Umits  are  not  more  or 
less  definitely  set  by  the  nature  of  the  subject,  it  is  neces- 
sary for  the  writer  to  determine  just  how  much  should  be 
included  for  the  particular  purposes  of  the  paper  and  just 
exactly  what  belongs  to  the  subject;  he  must,  in  other 
words,  draw  a  circle  very  definitely  about  his  subject. 
This  limitation  predetermined,  there  remains  the  still 
harder  task  of  guarding  constantly  against  stepping 
beyond  it. 

An  example  or  two  will  make  this  principle  clearer. 
If  a  writer  is  explaining  the  various  methods  of  wood 
preservation  by  impregnation  of  the  wood-fiber  with 
creosote  and  other  preservatives,  he  must  not  allow  a 
chance  reference  to  the  necessity  of  conserving  lumber 
to  sidetrack  him  upon  a  discussion  of  conservation  prob- 
lems and  a  tirade  against  timber  thieves;  these  are  interest- 
ing matters,  but  they  are  not  a  part  of  his  immediate 
subject.  Long-winded  and  ponderous  introductions  are 
the  worst  offenders  against  unity.  A  description  of  a 
recent  improvement  in  an  electric  cooker  need  not  begin 
with  a  history  of  the  cook-stove,  and  it  is  not  necessary  to 
introduce  an  explanation  of  the  process  of  lumbering  with 
a  two-paragraph  glorification  of  the  forest  primeval.     The 


THE  WHOLE  COMPOSITION  25 

writer  should  know  definitely  what  the  limits  of  his 
subject  are  and  then  should  stay  within  those  limits  from 
beginning  to  end. 

One  of  the  most  effective  ways  of  forcing  an  observance 
of  unity  is  for  the  writer  to  state  definitely  at  the  begin- 
ning of  his  paper  the  limits  of  his  subject.  The  value  of 
such  a  device  is  twofold:  first,  it  gives  the  reader  at  once 
a  definite  idea  of  what  the  subject  and  its  limits  are,  so 
that  he  knows  from  the  beginning  what  the  paper  is 
about;  second,  if  the  writer  keeps  his  own  statement  of 
limitation  clearly  in  mind,  he  is  far  less  likely  to  wander 
from  his  subject.  Of  course,  in  forming  his  statement 
of  limitations,  he  will  not  find  it  necessary  always  to  use 
the  same  stereotyped  phrases.  He  need  not  always  say, 
■'It  is  my  purpose,  etc.,"  or  "This  paper  will  take  up, 
etc."  The  information  given  must  be  modified  to  suit 
the  subject,  and  the  baldness  of  the  device  as  a  piece  of 
compositional  machinery  can  be  concealed  in  a  hundred 
different  ways. 

Even  more  important  than  the  principle  of  Unity  in 
the  whole  composition  is  the  principle  of  Coherence,  the 
sticking-together  of  the  various  parts  of  the  composition. 
Good  unity  comes  mainly  from  a  careful  selection  of  the 
details  which  go  into  the  paper;  good  coherence  comes 
principally  from  a  careful  arrangement  of  those  details. 
A  disassembled  machine  lying  on  the  floor  in  a  heap  of 
parts  may  certainly  be  said  to  possess  unity,  potentially 
at  least,  since  all  the  necessary  parts  and  no  more  are 
present ;  coherence  it  does  not  have  until  a  skilled  mechanic 
puts  all  the  parts  together  in  their  proper  relationship 
one  to  another.  Similarly,  a  writer  may  have  deter- 
mined accurately  enough  just  what  should  go  into  his 
paper,  but  if  he  then  throws  his  ideas  together  with  no 


26    COMPOSITION  OF  TECHNICAL  PAPERS 

regard  for  good  order,  the  result  will  be  chaos.  Careful 
planning  and  organization  is  as  essential  to  a  paper  as  it 
is  to  a  machine.  And  yet  many  a  writer  will  plunge  in 
at  one  end  of  a  composition  with  only  the  vaguest  idea 
of  the  course  which  he  will  take. 

Good  coherence  in  a  paper  can  not  be  secured  without, 
first,  a  careful  division  into  parts,  and,  second,  a  logical 
arrangement  of  those  divisions.  Just  what  the  best 
division  and  arrangement  of  parts  of  any  composition 
is  will  be  determined  largely,  of  course,  by  the  nature  of 
the  subject.  Some  subjects  are,  obviously,  more  easy 
to  handle  than  others.  An  explanation  of  a  process  of 
manufacture,  for  example,  will  naturally  follow  a  chrono- 
logical arrangement,  the  different  parts  of  the  composition 
corresponding  to  the  various  stages  in  the  process.  An 
expository  description  of  a  machine  will  usually  be 
built  up  by  giving  first  a  general  idea  of  the  principle  of 
operation  and  of  the  essential  structure  of  the  machine, 
which  will  serve  as  a  basis  for  the  reader's  understanding 
of  the  details,  and  then  a  description  of  the  details  grouped 
in  some  regular  order  which  must  be  determined  by 
the  nature  of  the  subject.  Compositions  dealing  with 
subjects  less  concrete  are,  of  course,  much  harder  to 
handle.  Each  of  such  subjects  presents  its  own  prob- 
lem. The  writer  must  in  all  such  cases  work  through 
his  material  very  carefully,  determine  into  just  what 
divisions  the  material  had  best  be  separated  and  just 
what  the  clearest  and  in  general  most  effective  arrange- 
ment of  these  divisions  will  be.  It  will  often  be  found 
that  the  divisions  of  the  subject  may  be  arranged  in  the 
order  of  importance,  either  the  most  important  first,  or, 
if  the  writer  wishes  a  strong  climax,  sometimes  last. 
Often,  too,  in  the  case  of  certain  subjects,  the  general 


THE  WHOLE  COMPOSITION  27 

explanation  must  precede  the  details;  this  arrangement 
is  sometimes  obviously  necessary  since  it  would  be  im- 
possible for  the  reader  to  understand  the  specific  details 
without  having  first  read  the  general  explanation.  Quite 
frequently  the  order  of  divisions  is  determined  by  the 
circumstance  that  any  other  arrangement  would  be  illogical 
and  unintelligible.  In  general,  too,  the  arrangement 
will  often  be  determined  largely  by  the  audience  ad- 
dressed and  by  the  specific  aim  of  the  writer.  Examples 
of  various  arrangements  of  material  are  given  in  the 
specimen  outlines  on  pages  34-43. 

Whatever  type  of  exposition  the  writer  may  be  con- 
cerned with,  and  however  simple  the  problem  of  arrange- 
ment may  be,  it  is  almost  always  best  for  him  to  make  a 
written  outline  before  beginning  to  write.  Many  writers 
like  to  claim  that  they  "never  make  an  outline."  Now 
what  these  writers  really  mean  is  that  they  never  make 
a  written  outline;  it  is  almost  inconceivable  that  any 
writer  would  plunge  into  a  composition  without  having 
some  notion,  however  ill-defined,  of  what  he  is  going  to 
say  and  of  how  he  is  going  to  say  it.  In  the  case  of  very 
short  compositions  and  of  those  with  a  very  simple 
arrangement  of  parts,  it  is  possible  and  permissible 
for  the  writer  to  make  and  carry  the  outline  in  his  mind, 
as  an  impromptu  speaker  does  when  suddenly  called 
upon  for  an  after-dinner  speech.  With  longer  and  more 
complex  pieces  of  work,  however,  not  to  make  a  pretty 
definite  written  plan  of  the  composition  is  to  be  extremely 
negligent.  A  contractor  might  build  a  chicken-coop  for 
himself  without  any  blueprint  to  guide  him;  but  if  he 
were  to  attempt  to  build  a  three-story  dwelling-house  for 
somebody  else  without  a  very  exact  set  of  plans  and  speci- 
fications, he  would  probably  be  called  a  fool  and  released 


28    COMPOSITION  OF  TECHNICAL  PAPERS 

on  the  spot.  Now  a  piece  of  writing  is  just  as  much  a 
problem  of  organization,  of  putting  parts  together  prop- 
erly, as  is  a  building,  and  if  the  writer  would  build  his 
composition  well,  it  is  as  necessary  that  he  should  have  a 
guide  to  go  by  as  that  the  contractor  should  have  his  blue- 
prints. To  write  without  such  a  guide  results  invariably 
in  a  waste  of  energy  and  time  and  almost  as  certainly 
in  an  incoherently  arranged  piece  of  exposition. 

Concerning  the  value  of  the  written  outline  the  Sug- 
^      gesHons  to  Authors,  published  by  the  American  Institute 
of  Electrical  Engineers,  says: 

"The  task  of  preparing  a  technical  paper  is  greatly  light- 
ened by  constructing  and  following  a  weU-considered  plan, 
and  no  writer  should  undertake  to  prepare  a  paper  without 
first  preparing  a  definite  plan  upon  which  his  paper  is  to  be 
constructed.  The  simplest  way  to  do  this  is  to  make  an  out- 
line or  skeleton  of  the  paper  similar  to  a  table  of  contents, 
using  a  separate  heading  for  each  main  division  of  the  subject 
and  appropriate  sub-heads  under  each  heading  to  cover  sub- 
divisions of  the  subject.  This  affords  a  ready  means  of 
arranging  the  contents  of  the  paper  in  logical  order,  and  the 
actual  writing  of  the  paper  consists  merely  in  filling  in  one 
or  more  paragraphs  under  each  head. 
;  "Another  method  preferred  by  some  authors  is  to  write 

upon  cards  hints  and  suggestions  in  regard  to  the  paper,  and 
when  ready  to  prepare  the  manuscript,  sort  out  the  cards  in 
their  proper  sequence.  Then  expand  the  suggestion  on  each 
card  into  one  or  more  paragraphs  which  fully  express  the  ideas 
which  the  writer  intends  to  convey." 

Aside  from  the  written  plan  as  a  guide,  the  mere 
exercise  of  working  over  the  outline  clarifies  one's  ideas 
and  gives  one  a  much  firmer  grasp  of  his  material.  A 
well-known  hydraulic  engineer  once  remarked  that  he 


THE  WHOLE  COMPOSITION  29 

found  the  mere  practice  of  outlining  his  knowledge  of 
any  subject  excellent,  since  it  gave  him  a  clearer  concep- 
tion of  the  relation  and  comparative  values  of  divisions 
under  the  subject.  It  is  well,  then,  if  the  writer  wishes 
to  have  a  coherent  arrangement  of  his  subject  and  to  give 
himself  a  clear  idea  of  the  relation  of  parts  for  him  to 
make  a  written  plan  before  he  begins  the  actual  writing, 
to  draw  a  chart,  so  to  speak,  of  the  proposed  journey. 

The  mere  form  which  an  outline  should  have  is  not  so 
essential  as  that  it  should  be  logically  sound  and  there- 
fore an  adequate  guide  to  the  writer.  For  after  all,  an 
outline,  useful  as  it  is,  is  only  a  working  plan  and  is  of 
no  more  value  to  the  writer  after  his  paper  is  in  final  form 
than  is  the  plan  of  a  house  to  the  persons  living  in  the 
finished  structure.  It  usually  happens,  especially  in  the 
case  of  long  papers,  that  the  fuller  the  outline  is  in  ground 
covered  and  in  statement,  the  better  it  is,  and  for  this 
reason  an  outline  which  is  a  complete  synopsis  of  the 
exposition  is  usually  the  best.  But  the  true  test  of  the 
value  of  an  outline  lies,  after  all,  in  its  logical  soundness 
and  in  its  consequent  adequacy  as  a  reliable  guide,  and 
for  this  reason  an  outline  which  is  merely  a  list  of  titles 
of  the  main  divisions  with  a  similar  list  of  the  sub-divi- 
sions may  be  quite  as  satisfactory  for  a  working  plan, 
provided  that  the  writer  has  organized  his  subject  thor- 
oughly, as  a  fuller  one.  The  weakness  of  such  an  abbre- 
viated outline  is  that  it  does  not  pin  the  writer  down 
quite  so  rigidly  to  his  plan;  its  meshes  are  wider,  and 
there  is  more  chance  of  his  slipping '  out.  But  if  it  is 
correctly  and  logically  constructed,  and  if  the  writer  has 
his  material  well  in  hand,  it  will  be  quite  sufficient  for 
his  purposes,  especially  if  his  paper  is  a  short  composition 
with  no  great  complexity. 


30    COMPOSITION  OF  TECHNICAL  PAPERS 

But  whether  the  full  synoptical  or  the  short  topical 
form  be  used,  the  outline,  in  order  to  be  a  reliable  guide, 
must  in  either  case  set  forth  the  true  relationship  of 
parts  in  the  composition.  What  is  meant  by  logical 
soundness  in  an  outline  may  be  illustrated  in  a  simple 
hypothetical  case.  Let  it  be  assumed  that,  omitting  a 
possible  introduction  and  conclusion,  an  examination  of 
the  subject-matter  of  a  proposed  paper  shows  it  to  fall 
into  three  main  divisions,  I,  II,  and  III,  that  a  further 
examination  shows  each  division  to  be  made  up  of  three 
sub-divisions.  A,  B,  and  C,  and  that  finally  each  sub- 
division is  found  to  have  three  parts,  i,  2,  and  3.  The 
outline,  represented  by  the  mere  symbols  would  then  be: 

I 

A 

I 

2 

3 

B 

I 

2 

3 

C 

I 

2 

3 • 

II 

A 

I 

2 

3 

B 

i: 

2 


THE  WHOLE  COMPOSITION  31 

3 

C 

I 

2 

3 

Ill 

A 

I 

2 

3 

B 

I 

2 

3 

C 

I 

2 

3 ••• 

An  actual  outline  would  not,  of  course,  present  such 
uniformity  as  does  this  hypothetical  one.  Now  if  this 
outline  has  been  properly  constructed,  an  examination 
of  it  will  show  all  divisions  which  are  given  equal  rank  to 
be  actually  coordinate,  although  not  necessarily  of  equal 
importance.  For  example,  I,  II,  and  III  must  be  coordi- 
nate; and  under  each  of  these  divisions.  A,  B,  and  C  must 
be  coordinate.  Furthermore,  if  the  outline  has  been 
properly  constructed,  an  examination  will  show  that 
each  sub-division  is  a  true  sub-division  of  the  governing 
division  under  which  it  stands.  For  example,  i,  2,  and 
3  under  I  B  must  all  be  factors,  so  to  speak,  of  I  B ;  it 
will  not  do  for  one  of  them  to  belong  under,  let  us  say, 
II  B.  If  the  outHne  has  been  solidly  constructed,  in 
other  words,  the  following  equations  will  prove  true: 


32     COMPOSITION  OF  TECHNICAL  PAPERS 

A+B+C  =  I, 

I  +  2  +  3  =  I  A, 

1+  2+3  =  1  B,  and  so  on  for  each  division. 

The  sum  of  the  coordinate  sub-divisions  will  in  each  case 
be  equivalent  to  their  governing  division. 

The  following  outline  of  a  descriptive-exposition  is 
'y^^       manifestly  defective: 


^V^ 


Mississippi  River  Survey  Boat 


I.  The  party. 

A.  Why  it  is  necessary  to  have  a  boat. 

B.  Organization  of  the  party. 

II.  Outside  appearance  of  the  boat. 

A.  General  appearance. 

B.  Method  of  mooring  the  boat. 

III.  Interior  of  the  boat. 

A.  Beds. 

B.  Drafting  table. 

C.  Dining  table  and  benches. 

D.  Ice  box. 

E.  Kitchen  which  included  the  stove,  cupboards,  etc. 

It  will  be  observed  here,  first,  that  the  major  divisions, 
I,  II,  and  III,  are  not  coordinate,  I  being  clearly  intro- 
ductory to  the  other  two.  The  sub-divisions  are  also 
illogical.  I  A  does  not  belong  under  I;  II  A  is  practically 
equivalent  to  II,  and  II  B  has  nothing  whatever  to  do 
with  II;  and  under  III  there  is  no  reason  for  the  "stove, 
cupboards,  etc.,"  being  lumped  together  while  the  ice 
box,  beds,  and  other  articles  of  furniture  are  dignified 
by  separate  division.  The  reader  might  assume  from 
the  outline,  moreover,  that  the  crew  cooked,  ate,  slept, 
and  worked  in  the  kitchen  since  no  other  room  is  men- 


THE  WHOLE  COMPOSITION  33 

tioned;  even  the  kitchen,  according  to  the  outhne,  is  of  no 
more  importance  as  a  whole  than  any  one  of  the  articles 
of  furniture  mentioned  under  III  A,  B,  C,  and  D. 

An  attempt  has  been  made  in  the  following  revision 
to  correct  these  errors: 

A  Mississippi  River  Survey  Boat 

Introduction: 
I.  Definition  of  a  survey  or  "quarter"  boat. 
II.  The  necessity  for  such  a  boat. 
III.  The  "crew"  of  the  boat. 

Body: 
I.  The  exterior  of  a  typical  survey  boat. 

A.  General  appearance  and  dimensions. 

B.  The  raft  part. 

C.  The  house  part. 

II.  The  interior  of  the  boat. 

A.  General  appearance  and  division  into  rooms. 

B.  The  living-room. 

1.  General  appearance  and  dimensions. 

2.  Furniture. 

C.  The  kitchen. 

1.  General  appearance  and  dimensions. 

2.  Furniture. 

Before  the  series  of  outlines  of  various  types  which 
follows  is  examined,  one  final  word  needs  to  be  said 
about  outhning.  It  should  always  be  remembered  that 
an  outline  should  not  be  used  slavishly;  if  it  is  found  after 
a  part  of  the  paper  has  been  written  that  the  outline  can 
be  improved,  this  improvement  should  always  be  made 
even  to  the  extent  of  throwing  the  outline  away  and  be- 
ginning all  over.  It  is  very  seldom  that  a  house  is  com- 
pleted exactly  in  accordance  with  the  original  plans,  and 


34     COMPOSITION  OF  TECHNICAL  PAPERS 

it  very  often  happens  that  a  composition  is  not  finished 
according  to  the  first  outhne.  On  the  other  hand,  if  an 
outline  has  been  thoughtfully  and  carefully  made,  the 
writer  should  be  slow  to  change  it  unless  he  is  certain  that 
his  reorganization  will  result  in  better  coherence. 

The  following  outlines  will  serve  as  illustrations  of  the 
principles  of  outlining. 

Outline  i 

The  Electric  Furnace 
Introduction: 
■  I.  Definition. 
II.  General  description. 

III.  Principle  of  operation. 

IV.  Uses. 

Body:  Detailed  description  of  the  essential  parts  of  the 
furnace. 

I.  The  resistor,  or  conducting  material  with  high  resist- 
ance. 
II.  The  envelope  of  refractory  material. 

III.  The  electrodes. 

IV.  The  metal  clamps  to  hold  the  electrodes  in  place  and 
make  connections  with  the  cables  of  the  circuit. 

V.  The  accessories,  consisting  of: 

A.  Cables. 

B.  Measuring  instruments. 

C.  Regulating  devices. 

Outline  2 

The  Two-cycle  Gas  Engine 
Introduction: 
I.  The   principle   of   operation   of   internal-combustion 

engines. 
II.  Definition  of  the  two-cycle  gas  engine. 


THE  WHOLE  COMPOSITION  35 


Body: 

I.  Description. 

A. 

Cylinder. 

B. 

Crank  case. 

C. 

Piston. 

D. 

Connecting  rod. 

E. 

Crankshaft. 

F. 

Flywheel. 

II.  Operation. 

A. 

Admission  of  gas. 

B. 

Compression  in  crank  case. 

C. 

Admission  to  cylinder. 

D. 

Compression. 

E. 

Explosion  and  working  stroke. 

F. 

Exhaust. 

Conclusion : 
I.  Uses  of  the  engine. 

II.  Advantages  over  other  types.  •'^ 

III.  Disadvantages. 

Outline  3 

Rating  a  Water-current  Meter 

Introduction: 
I.  Definition  of  the  meter. 
II.  General  outline  of  the  method  of  rating. 

Body: 
I.  Method  of  making  the  rating. 

A.  Preliminary  steps. 

1.  Laying  out  the  base  line. 

2.  Setting  the  transits. 

3.  Hanging  the  meter. 

4.  Arranging  the  block  and  tackle. 

B.  Final  rating. 

1.  Moving  the  boat. 

2.  Timing  the  velocity. 


36    COMPOSITION  OF  TECHNICAL  PAPERS 

3.  Counting  the  revolutions. 
II.  The  use  of  the  data  obtained. 


Outline  4 

The  Laying   of  Underground   Concrete   Conduits 

Introduction: 
I.  Underground  conduits  in  general;  definition  and  uses, 
II.  The  all-concrete  conduits. 

Body: 
I.  Parts  used  in  laying  concrete  conduits. 

A.  Chairs. 

B.  Wooden  molds. 

C.  Weights. 

D.  Slabs. 

II.  Method  of  laying  the  ducts. 

A.  Excavating. 

B.  Laying  the  concrete  foundation. 

C.  Placing  the  chairs,  molds,  and  weights. 

D.  Pouring  the  cement. 

E.  Drawing  the  molds. 

F.  Laying  the  slabs. 

1.  Pointing  up. 

2.  Cleaning  the  ducts. 

G.  Adding  the  successive  layers. 
H.  Topping  off  and  filling. 

Conclusion: 
I.  Advantages  of  the  all-concrete  ducts. 
II.  Disadvantages  of  the  all-concrete  ducts. 

Outline  5 

How  Photographs  Are  Made 

Introduction: 
I.  Definition  of  photography. 


THE  WHOLE  COMPOSITION  37 

II.  Brief  outline  of  the  essential  steps  in  the  making  of 
photographs. 

III.  Description  of  the  camera. 

A.  Essential  form  and  details. 

B.  Classification  into  principal  types. 

IV.  Announcement  that  this  explanation  will  be  concerned 
only  with  the  taking  of  photographs  with  a  plate 
camera  having  a  fixed  focus. 

Body: 
I.  Loading  the  camera. 

A.  Definition  of  this  stage  of  the  process. 

B.  The  plate-holder. 

C.  The  plate. 

D.  Loading  the  holder. 

E.  Putting  the  holder  into  the  camera. 
II.  Making  the  exposure. 

A.  Definition  of  this  stage  of  the  process. 

B.  Timing  the  exposure  according  to: 

1.  Intensity  of  light. 

2.  Nature  of  the  object  photographed. 

C.  Removing  the  plate-holder  slide. 

D.  Releasing  the  shutter. 

E.  Replacing  the  plate-holder  slide. 
III.  Making  the  negative. 

A.  Definition  of  this  stage  of  the  process. 

B.  Classification  of  methods  used  into: 

1.  Hand  method. 

2.  Tank  method. 

C.  Explanation  of  the  two  processes. 
I.  Hand  method. 

a.  General  outline  of  the  process. 

b.  Preparing  the  baths. 

c.  Developing  the  plate. 

d.  Rinsing  the  plate. 

e.  Fixing  the  plate. 


38     COMPOSITION  OF  TECHNICAL  PAPERS 

f.  Washing  the  negative. 

g.  Drying  the  negative. 
2.  Tank  method. 

a.  Essential  differences  between  tank  and  hand 
methods. 

b.  Description  of  the  tank. 

c.  Preparing  the  baths. 

d.  Developing  the  plate. 

e.  Rinsing  the  plate. 

f.  Fixing  the  plate. 

g.  Washing  the  negatives.        * 
h.  Drying  the  negatives. 

IV.  Making  the  print. 

A.  Definition  of  this  stage  of  the  process. 

B.  Limitation  of  the  subject  to  printing  by  artificial 
light. 

C.  Preparing  the  baths. 

D.  Making  the  exposure. 

E.  Developing  the  print. 

F.  Rinsing  the  print. 

G.  Fixing  the  print. 
H.  Washing  the  print. 

I.  Drying  the  print. 

Conclusion: 

General  hints  and  suggestions  for  the  successful  taking  of 
photographs. 

Outline  6 
The  Sanderson  X-ray  Machine 
Introduction: 
I.  The  increasing  field  of  the  X-ray  tube  in: 

A.  Radiography. 

B.  Fluoroscopy. 

C.  Therapy. 

II.  Conditions  which  stimulated  the  development  of  the 
Sanderson  machine. 


THE  WHOLE  COMPOSITION  39 

Body: 
I.  Electrical  principles  of  the  machine  with  diagram  of 
connections. 
II.  Enumeration  and  description  of  parts  as  fulfilling  the 
electrical  functions  above  mentioned. 

A.  Rotary  converter:  synchronous  motor. 

B.  Transformer. 

C.  Rectifier. 

D.  Spark  points. 

E.  Control  switchboard. 

F.  Tube. 

III.  Assembling  of  the  apparatus. 

A.  Transformer  cabinet. 

B.  Switchboard. 

IV.  Operating  merits  of  the  machine. 

A.  Electrical. 

B.  Mechanical. 

C.  Assemblage. 

Conclusion: 
The  complete  success  of  the  Sanderson  machine  in  solving 
the  different  problems  of  X-ray  work. 

Outline  7 

Proposed  Reorganization  of  an  Electrical  Testing 
Laboratory 
Introduction: 
I.  A  testing  room  is  absolutely  necessary: 

A.  To  make  certain  that  apparatus  will  do  the  work 
for  which  it  was  designed. 

B.  To  ascertain -whether  apparatus  has  been  built  as 
designed. 

C.  To  check  the  mechanical  strength  and  the  machine 
work. 

D.  For  purposes  of  advertisement. 

II.  The  requirements  of  an  electrical  testing  room  are: 


40    COMPOSITION  OF  TECHNICAL  PAPERS 

A.  It  must  be  in  close  proximity  to  the  shipping  room. 

B.  It  must  be  easy  of  access  to  all  departments  of  the 
shop. 

C.  It  must  be  sufficiently  equipped  with: 

1.  Ammeters  and  voltmeters. 

2.  Testing  boards. 

3.  Rheostats. 

4.  Motors. 

5.  Testing  benches. 

D.  It  must  be  under  efficient  management. 

E.  Its  managers  must  keep  good  permanent  records. 

Body: 
I.  The  objections  to  the  present  testing  room  at  the 
M —  manufacturing  plant  are: 

A.  It  is  poorly  located. 

B.  There  is  no  arrangement  for  future  expansion. 

C.  The  branch  testing  rooms  are  too  widely  distributed. 

D.  The  equipment  is  antiquated. 

E.  The  management  is  inefl5cient. 

F.  The  records  are  badly  kept. 

II.  The  following  changes  should  be  made: 

A.  The  testing  room  should  be  put  into  a  new  building 
offering  better  opportunity  for  expansion. 

B.  The  room  should  be  located: 

1.  Nearer  to  the  shipping  room. 

2.  Nearer  to  the  source  of  electric  power. 

3.  Nearer  to  the  two  elevators. 

C.  The  room  should  be  reequipped. 

D.  The  present  apparatus  should  be  rearranged. 

E.  The  management  should  be  reorganized  so  that : 

1.  A  foreman  has  charge  of  each  bench. 

2.  Unskilled  labor  is  used  for  minor  testing. 

F.  The  records  should  be  more  systematically  kept. 

Conclusion: 
If  the  proposed  changes  are  carried  out,  the  result  will  be: 


THE  WHOLE  COMPOSITION  41 

A.  A  certain  saving  of  money. 

B.  Provision  for  future  expansion. 

The  following  three  outlines  are  the  tables  of  contents  of 
three  technical  papers  published  by  the  Bureau  of  Mines. ^  It 
will  be  observed  that  such  tables  are  in  effect  brief  outlines. 

Outline  8 

The  Rate  of  Burning  of  Fuse  as  Influenced  by  Temperature 
AND  Pressure 

By   W.    O.    Snelling   and   Willard    C.    Cope 
Introduction : 

Nature  and  composition  of  fuse. 

Descriptive  terms. 

Composition  of  fuse  powder. 
Rate  of  burning. 

Normal  rate  of  burning. 

Influence  of  pressure. 

Influence  of  temperature. 

Influence  of  moisture. 

Influence  of  mechanical  injury. 
Practical  conclusions. 

Outline  9 
Methods  of  Analyzing  Coal  and  Coke 
By  F.  M.  Stanton  and  A.  C.  Field ner 
Introduction : 

Preliminary  treatment  of  samples. 
Methods  of  analysis. 
Moisture. 
Ash. 

Volatile  matter. 
Sulphur. 
Carbon  and  hydrogen. 

*  Reprinted  by  permission  of  the  Bureau  of  Mines. 


42     COMPOSITION  OF  TECHNICAL  PAPERS 

Nitrogen. 

Phosphorus. 
Determination  of  the  calorific  value  of  coal. 

Standardization  of  the  calorimeter. 
Determination  of  the  true  specific  gravity  of  coal  and  coke 

substance. 
Determination  of  the  apparent  specific  gravity.  ' 

Outline  lo 

The  Factor  of  Safety  in  Mine  Electrical  Installations 

By  H.  H.  Clark 
Introduction: 
Classification  of  accidents  due  to  electricity. 

Electric  shocks. 

Danger  from  ground-return  circuits. 

Dangers  from  trolley  wires  or  bare  conductors. 

Danger  from  accidental  charging  of  equipment. 

Shocks  from  locomotives  and  cars. 

Relative  danger  from  different  voltages. 
Fires  caused  by  electricity. 
Explosions  caused  by  electricity. 

Ignition  of  explosives. 

Accidents  due  to  electrical  shot  firing. 

Ignition  of  gas. 

Ignition  of  coal  dust. 
Conditions  surrounding  electrical  installations  in  mines. 

Physical  conditions. 

Temporary  character  of  installations. 
The  prevention  of  accidents  caused  by  electricity. 

Elimination  of  contributory  causes. 

Confinement  of  the  current. 

Additional  precautions. 

Maintenance  of  safety  factor. 
Summary. 


THE  WHOLE  COMPOSITION  43 

To  secure  good  coherence  in  an  exposition  it  is  neces- 
sary not  only  to  arrange  the  material  clearly  and  logically, 
but  also  to  make  the  arrangement  clear  to  the  reader 
lest  he  plunge  from  one  division  into  the  next  without 
realizing  that  he  is  taking  up  a  new  part  of  the  composi- 
tion. It  is  not  alone  sufficient  that  the  arrangement  be 
clear  in  the  writer's  mind;  he  must  communicate  the  plan 
to  his  reader.  A  cataloguer  who  has  classified  and  shelved 
the  books  in  his  library  knows  just  where  each  division 
begins;  a  stranger  in  the  book-stacks,  however,  would 
have  great  difficulty  in  determining  what  classification 
had  been  made  were  it  not  for  the  various  labels  and 
guides  which  direct  him  to  the  different  sections.  Lest 
the  reader  be  lost  in  the  composition,  the  writer  must 
similarly  direct  him  on  the  course. 

This  guiding  of  the  reader  is  accomplished  by  what  are 
usually  known  as  transition  devices,  hints  worked  into 
the  first,  or  near  the  first,  of  a  new  division,  which  con- 
vey to  the  reader  the  information  that  the  writer  has 
finished  what  he  has  to  say  about  the  part  of  the  subject 
with  which  he  has  been  dealing  and  is  ready  to  go  on  to 
another  division.  Usually  a  transition  sentence  consists 
of  two  parts;  the  first  echoes  the  division  just  completed, 
and  the  second  announces  the  new  division.  Such  a 
device  is  illustrated  in  the  following  sentences: 

"Although  easier  to  handle  than  the  folding  camera, 
the  box  camera  is  much  inferior  in  the  quality  of  the  work 
which  it  does." 

"Even  more  interesting  than  the  developing  of  the 
plate  is  the  next  step  in  the  process  of  making  a  photo- 
graph, the  printing  of  the  picture." 

It  is  easy  to  see  from  these  two  sentences  both  the  sub- 
ject of  the  division  just  completed  and  that  of  the  divi- 


44     COMPOSITION  OF  TECHNICAL  PAPERS 

sion  being  introduced.  Sometimes  a  mere  word  or  phrase 
is  enough  to  show  that  a  change  of  subject  is  occurring, 
and  sometimes,  where  the  divisions  are  very  distinct  and 
are  announced  clearly  in  the  first  sentence  of  each  divi- 
sion, no  transition  device  is  necessary  at  all.  To  avoid 
monotony  and  stiffness  it  is  always  well  to  vary  the  de- 
vices used.  But  whatever  device  is  employed,  each 
change  of  subject  should  be  at  once  apparent  to  the 
reader;  he  should  always  know  just  up  to  what  point  in 
the  paper  he  has  arrived. 

Of  the  cardinal  principles  governing  the  planning  and 
writing  of  the  composition  as  a  whole  unity  and  coherence 
have  so  far  been  explained  and  illustrated.  There  still 
remains  to  be  considered  the  principle  of  Proportion^ 
which  directs  that  the  relative  length  of  the  different 
parts  of  a  composition  be  made  to  correspond  to  the 
relative  importance  of  the  subject-matter  of  the  divisions. 
Of  the  three  principles  considered  this  is  the  least  im- 
portant and  the  most  easy  to  follow. 

To  get  good  proportion  in  his  composition  the  writer 
must  be  careful  to  write  everything  to  scale;  that  is,  he 
must  be  careful  to  make  the  length  of  each  division  corre- 
spond, in  general,  to  its  importance.  Ordinarily,  pro- 
portion takes  care  of  itself,  for  it  is  natural  to  develop 
most  fully  those  divisions  of  the  subject  which  are  the 
most  important.  Sometimes,  however,  the  writer  may 
find  himself  in  possession  of  more  information  on  a 
relatively  unimportant  division  than  he  has  on  a  relatively 
important  one,  and  if  he  is  not  careful,  he  will  over- 
develop the  unimportant  division.  The  obvious  method 
of  avoiding  this  error  is  for  him  to  increase  his  knowledge 
of  the  important  division;  if  he  does  not  do  this,  the  reader 


THE  WHOLE  COMPOSITION  45 

is  likely  to  get  a  badly  distorted  conception  of  the  rela- 
tive values  of  the  two  divisions. 

One  final  word  needs  to  be  said  about  the  application 
of  the  principles  of  unity,  coherence,  and  proportion. 
No  amount  of  study  of  abstract  principles  will  in  itself 
make  a  writer  of  any  man.  Men  learn  to  swim  by 
swimming,  not  by  reading  books  on  the  art.  And  they 
learn  to  write  very  largely  by  writing,  and  no  study  of 
principles,  deduced  from  the  successful  writing  of  other 
men,  will  assist  a  writer  unless  he  tries  consciously  to  use 
them  or  unless  he  absorbs  them  so  completely  that  he 
employs  them  unconsciously. 

It  should  be  remembered,  moreover,  that  each  com- 
position presents  to  a  certain  extent  a  new  problem  which 
no  one  has  faced  before.  For  this  reason  the  general 
principles  explained  must  be  used  intelligently  in  rela- 
tion to  the  problem  presented.  Intelligently  employed, 
they  will  assist  in  giving  to  the  writing  of  any  man  the 
effectiveness  which  they  have  given  to  the  writing  of 
others. 

Some  special  problems  which  still  remain  to  be  con- 
sidered with  the  explanation  of  the  general  principles  of 
planning  and  writing  the  whole  composition  are  the  title, 
the  introduction  and  conclusion,  and  the  literary  style. 

The  Title 

The  title  is  the  name  of  the  composition;  like  the  label 
on  a  bottle  it  should  indicate  the  contents.  It  is  the 
first  part  of  an  article  which  the  reader  sees  and  very  often 
that  which  remains  longest  in  his  mind.  For  these 
reasons  a  careful  selection  of  a  title  is  more  necessary  than 
the  writer  usually  imagines. 


46     COMPOSITION  OF  TECHNICAL  PAPERS 

Readers  ordinarily  depend  upon  the  title  in  deciding 
whether  or  not  to  read  a  given  article,  and  the  writer 
whose  title  is  ambiguous  or  inaccurate  in  its  indication 
of  the  subject-matter  misleads  his  reader.  The  title 
should,  moreover,  be  brief;  usually  it  need  only  suggest 
the  general  subject,  not  give  all  of  the  details  considered. 
It  should  indicate  the  point  of  view  of  the  writer;  there 
is  a  great  difference,  for  example,  between  How  to  Lay 
a  Concrete  Sidewalk^  which  suggests  directions  to  a 
workman,  and  How  a  Concrete  Sidewalk  is  Laid,  which 
suggests  a  mere  explanation  of  the  process.  In  addi- 
tion to  being  given  all  these  essential  qualities  the  title 
can  usually  be  made  pleasing  and  attractive.  A  Novel 
Method  of  Street  Lighting  is  a  more  attractive  title  than 
Lighting  a  Street  by  Arches  Fitted  with  Incandescent  Lamps; 
the  second  title  gives  more  than  is  necessary  of  the 
subject  and  is  much  clumsier  than  the  first.  Keeping 
in  Touch  with  Construction  Work  is  a  much  neater  and 
more  attractive  title  than  A  Suggested  Method  for  Getting 
Reports  and  Keeping  Records  of  Construction  Work.  The 
titles  of  the  technical  articles  in  Part  II  will  serve  as 
further  illustrations. 

The  Introduction 

The  self-conscious  formality  with  .which  the  average 
writer  approaches  the  important  and  terrifying  task  of 
writing  down  his  ideas  for  the  inspection  of  a  critical 
world  is  nowhere  more  in  evidence  than  in  the  ponderous 
and  irrelevant  introduction  which  usually  prefaces  an 
article.  The  notion  sometimes  exists  that  the  introduc- 
tion, like  the  overture  before  the  curtain  goes  up,  has 
no  real  connection  with  the  subject  of  the  paper.     Writers 


THE  WHOLE  COMPOSITION  47 

accordingly  begin  their  papers  with  matter  which  has 
often  only  the  remotest  connection  with  their  subjects. 
Usually  the  tendency  is  to  bring  in  the  ancient  history 
of  the  machine  or  process  described.  The  practice,  too, 
is  quite  frequent,  especially  in  an  address,  of  attempting 
to  put  the  audience  in  a  pleasant  frame  of  mind  by  relat- 
ing a  story  or  jest.  This  is  sometimes  legitimate  where 
the  anecdote  has  a  definite  point  and  can  be  immediately 
and  easily  connected  with  the  subject  under  discussion; 
where,  however,  like  the  auctioneer's  bell,  it  is  a  mere 
trick  for  getting  the  attention  of  the  audience,  it  becomes 
cheap  clap- trap.  Concerning  this  general  tendency  to 
write  irrelevant  introductions  the  Suggestions  to  Authors 
of  the  American  Institute  of  Electrical  Engineers  says: 

"The  tendency  to  preface  a  paper  with  a  long  and  burden- 
some prelude,  not  intimately  related  to  the  subject  under  dis- 
cussion, is  very  prevalent  but  should  be  avoided,  as  the  intro- 
duction of  unnecessary  or  irrelevant  matter  detracts  from  the 
value  of  a  technical  paper." 

It  should  never  be  forgotten  that  the  introduction, 
then,  far  from  being  a  mere  flourish  at  the  beginning,  is 
as  regular  and  legitimate  a  part  of  the  article  as  is  the 
body  or  argument  proper.  What,  then,  may  it  contain? 
While  it  is  impossible,  of  course,  to  give  specific  sugges- 
tions for  all  cases,  there  are  certain  elements  which  should 
be  found  in  almost  all  introductions  of  papers  of  any 
complexity  and  length. 

There  should  be,  first  of  all,  a  clear  announcement  of 
the  subject  so  that  the  reader  may  know  from  the  start 
what  he  is  reading  about.  This  announcement  need  not 
be  bald  and  unattractive.  Such  stiff  introductory  sen- 
tences as,  ''It  is  the  purpose  of  the  writer  of  this  paper 


48    COMPOSITION  OF  TECHNICAL  PAPERS 

to  call  attention  briefly  to  some  special  considerations 
arising  from  the  recent  failure  of  the  concrete  dam  at 
Riverfield,  California,"  and,  "This  paper  aims  to  de- 
scribe a  new  method  of  air  analysis"  are  effective  as 
announcements  but  awkward  in  expression.  It  is  much 
better  to  begin  with  some  positive  and  interesting 
statement  which  will  serve  at  once  to  introduce  the  sub- 
ject and  to  give  an  impulse  to  the  development  of  the 
thought.  The  first  sentence  above,  for  example,  might 
be  rewritten  as  follows:  *'The  recent  failure  of  the  con- 
crete dam  at  Riverfield,  California,  presents,  because  of 
the  experimental  nature  of  a  part  of  the  construction, 
some  problems  of  particular  interest  to  the  hydraulic 
engineer."  The  following  initial  sentence  of  a  short 
descriptive-exposition  is  at  once  simple  and  effective: 
"The  most  efficient  and  practicable  waterwheel  to  use 
where  a  small  flow  but  a  high  head  of  water  is  available 
is  the  impulse  wheel."  The  announcement  need  not 
occur  in  the  very  first  sentence.  Sometimes  it  is  better 
to  lead  up  to  it  as  in  the  following  introduction  from  a 
paper  entitled  Running  a  Line  over  a  Riven 

"The  surveyor,  especially  the  railroad  engineer/often  has 
to  find  the  exact  distance  from  one  place  to  another.  Ordi- 
narily this  distance  is  accurately  measured  with  a  graduated 
steel  tape  in  a  straight  line  between  the  two  points.  Very 
often,  however,  some  obstruction,  such  as  a  river,  prevents 
the  taping  of  the  distance,  and  so  the  engineer  has  to  resort 
to  some  indirect  taping  and  some  computation  in  order  to 
get  the  distance  of  the  line." 

In  addition  to  the  announcement  of  the  subject  the 
introduction  should  contain,  excepting  in  very  short 
articles,  some  indication  of  the  limitations  of  the  subject 
and  of  the  arrangements  of  the  various  parts.     These 


THE  WHOLE  COMPOSITION  49 

elements  in  an  introduction  assist  the  reader  to  an  under- 
standing of  the  scope  and  method  of  the  article  in  much 
the  same  way  that  the  table  of  contents  of  a  book  assists 
him  in  understanding  the  scope  of  the  book.  The  fol- 
lowing introduction  from  an  article  on  The  Strength  of 
Cement  Mortar  illustrates  this  principle: 

"The  strength  of  cement  mortars  i*s  affected  chiefly  by 
(i)  the  proportions  of  cement  used,  (2)  the  size  and  grading 
of  the  sand,  (3)  the  amount  of  water  used,  and  (4)  the  degree 
to  which  the  product  is  compacted.  The  effect  of  these 
factors  may  be  summed  into  two  general  laws:  (i)  the  strength 
increases  directly  with  the  proportion  of  cement  used;  and 
(2)  the  strength  for  a  given  proportion  of  cement  increases 
directly  with  the  density  of  the  mortar.  Law  (2)  expresses, 
in  a  general  way,  the  effect  of  the  sand,  of  the  amount  of  water, 
and  of  the  compactness  of  material." 

Other  elements  which  may  be  found  in  an  introduction 
assist,  in  general,  in  clearing  the  ground  for  an  under- 
standing of  the  body  of  the  paper.  Among  these  are 
indications  of  the  particular  aim  or  subject  of  the  writer, 
definitions  of  terms  used  in  the  paper,  and  all  preliminary 
explanations  which  may  be  found  necessary.  To  this 
last  category  belong  such  matters  as,  for  example,  the 
history  of  the  development  of  a  process  where  such  an 
account  would  assist  the  reader  in  understanding  the 
explanation  of  the  modern  process.  But  in  all  cases  the 
writer  must  be  careful  to  include  in  his  introductions^ 
nothing  which  is  not  actually  useful  to  his  reader  and 
relevant  to  his  subject. 

The  Conclusion 

It  is  difficult  to  begin  a  paper  properly;  it  is  sometimes 
even  more  difficult  to  close  it  properly.     The  writer  who 
4 


50    COMPOSITION  OF  TECHNICAL  PAPERS 

is  convinced  that  he  should  introduce  his  paper  with  a 
flourish  of  trumpets  is  also  certain  that  he  should  bow 
his  subject  formally  off  the  stage.  The  best  advice  for 
him  can  be  put  briefly:  "When  through,  stop."  It  is 
quite  legitimate  to  sum  up  very  briefly  the  points  devel- 
oped in  a  long  argument;  this  assists  the  reader  to  get  a 
brief  review  of  the  subject.  Usually,  however,  such  a 
summary  is  not  needed,  and  any  summing  up  which  re- 
peats the  details  of  the  discussion  is  an  insult  to  the  in- 
telligence of  the  reader  and  a  waste  of  his  and  the  writer's 
time  and  energy.  A  graceful  conclusion  to  the  paper, 
which  takes  away  the  bluntness  of  breaking  off  short, 
can  be  devised  without  a  vain  repetition  of  ideas  which 
the  reader  already  has  clearly  in  mind. 

A  conclusion,  then,  which  is  simply  a  formal  tag  to 
the  composition  and  which  merely  repeats  details  which 
have  already  been  made  clear  is  quite  useless.  An  exami- 
nation of  the  end  of  a  long  exposition  or  argument  will 
usually  show,  however,  that  the  writer  has  had  to  say 
by  the  way  of  conclusion  something  which  is  not  a  part 
of  the  body  of  the  article,  but  which  has,  nevertheless, 
an  important  relation  to  it.  Such  conclusions  take  a 
variety  of  forms.  In  a  long  argument,  for  example,  the 
writer  may  emphasize  the  value  of  his  reasoning  by 
establishing  in  the  conclusion  the  fact  that  he  has  taken 
an  unprejudiced  view  of  the  question.  A  writer,  again, 
who  has  been  explaining,  let  us  say,  a  social  or  economic 
condition,  may  conclude  with  a  hint  at  the  probable 
results  of  the  condition  of  affairs  which  he  has  outlined. 
Technical  descriptions  and  explanations  of  processes 
sometimes  end  with  a  statement  of  the  personnel  in- 
volved, the  name  of  the  inventor  and  manufacturer,  or 
of  the  constructing  company  and  engineers  being  given. 


THE  WHOLE  COMPOSITION  51 

Such  a  conclusion  has  obviously  nothing  directly  to  do 
with  the  body  of  the  article,  but  it  is,  nevertheless,  of 
interest  to  engineers.  The  technical  articles  in  Part  II 
provide  other  examples  of  typical  conclusions. 

Style 

Style  in  writing  can  not,  of  course,  in  its  finer  qualities 
be  taught.  A  so-called  good  style,  by  which  is  meant  a 
style  that  is  facile,  smooth,  clean-cut,  graceful,  varied, 
and  otherwise  rich  and  pleasing,  is  the  result  of  inborn 
ability  corrected  and  chastened  usually  by  long-continued 
reading  of  the  best  in  hterature.  In  the  writing  of 
technical  papers  the  chief  quality  to  be  desired  is,  of 
course,  clearness;  it  is  of  the  first  importance  that  the 
reader  understand  what  has  been  written.  The  qualities 
of  ease  and  grace  of  expression,  the  qualities  which  make 
an  article  pleasing  to  read,  are,  however,  by  no  means  to 
be  despised.  To  assist  in  obtaining  them  every  writer 
of  technical  papers  should  cultivate  the  habit  of  reading 
good  literature,  not  only  well-written  technical  books 
and  articles,  but  also  the  best  that  the  English  language 
has  to  offer  him  in  other  fields.  Many  a  professional 
man  who  has  never  had  an  academic  training  owes  his 
facihty  in  writing  to  his  habit  of  careful,  selective  reading. 

Although  the  subtler  elements  of  good  style  can  not 
be  gained  by  conscious  effort,  there  are  two  elements 
which  can  be  consciously  sought  and  which  add  greatly 
to  the  quahty  of  clearness.  They  are  conciseness  and 
concreteness.  Most  men  say  too  much;  few  men  say 
too  little.  Most  writers  occasionally  bury  their  thought 
under  an  avalanche  of  verbiage,  using  ten  words  where 
five  would  do.     They  need  to  acquire  the  habit  of  prun- 


52     COMPOSITION  OF  TECHNICAL  PAPERS 

ing  mercilessly,  of  cutting  off  phrases  which  they  can  do 
very  well  without.  "Steam  engines,"  writes  one,  ''may 
in  general  be  divided  into  two  classes.  The  first  class 
is  that  of  the  reciprocating  type,  and  the  second  class  is 
that  of  the  turbine  type."  How  much  more  concise  and 
effective  if  he  had  written  simply,  "Steam  engines  may 
be  divided  into  two  general  classes,  the  reciprocating 
type  and  the  turbine  type." 

An  even  more  important  habit  to  acquire  is  that  of  con- 
creteness.  The  preference  for  the  specific  and  concrete 
over  the  general  and  abstract  results  in  clearness  and 
color  in  the  exposition.  It  is  very  easy  to  leave  an  idea 
vague  and  unintelligible  for  want  of  illustration;  it  is 
almost  impossible,  on  the  other  hand,  to  over-illustrate. 
Specific  examples,  comparisons,  and  analogies  should, 
therefore,  be  used  freely  wherever  the  ideas  are  abstract 
and  likely  to  be  difficult  to  grasp.  All  such  comparisons 
and  illustrations  should  be  carefully  adapted  to  the  under- 
standing of  the  reader.  An  American,  for  example,  who 
is  explaining  the  game  of  baseball  to  an  Enghshman 
can  perhaps  do  no  better  than  to  compare  it  to  the  game 
of  cricket.  An  engineer  in  describing  to  another  engineer 
a  machine  with  which  the  listener  is  not  familiar  will 
naturally  compare  it  with  a  better  known  machine  which 
it  resembles;  if,  however,  he  is  attempting  to  describe 
the  same  machine  to  a  society  girl,  he  will  have  to  alter 
his  comparison.  In  general,  the  examples  and  analogies 
may  be  safely  drawn  from  the  experiences  of  daily  life 
with  the  assurance  on  the  part  of  the  writer  that  they  will 
assist  the  average  reader  in  his  understanding  of  much 
which  without  them  would  be  only  vague  and  indefinite. 


CHAPTER  IV 
THE  PARAGRAPH 

Introduction 

If  a  composition  were  to  be  presented  to  the  reader  in  a 
solid  mass,  with  each  margin  in  a  straight,  unbroken  Hne 
and  no  indication  whatever  of  the  underlying  scheme  of 
organization,  it  would  probably  seem  to  him  like  a  hope- 
less wilderness  of  ideas  through  which  it  would  be  tire- 
some if  not  impossible  to  find  a  way.  To  prevent  this 
feeling  a  composition  is  always  broken  up  into  divisions 
called  paragraphs.  Each  paragraph  is  set  off  distinctly 
by  being  begun  on  a  new  line,  which  is  indented  conspicu- 
ously from  the  left-hand  margin.  The  aim  of  paragraph- 
ing is  in  general  to  make  the  composition  clearer  and 
easier  to  read. 

Paragraphing  may  be  done  for  a  variety  of  specific 
reasons.  Sometimes  it  is  a  mere  visual  device  to  assist 
the  reader  to  pick  up  an  idea  quickly  or  to  make  one 
statement  stand  out  clearly  from  others  which  surround 
it.  Such  is  its  use  in  a  report,  for  example,  in  which  each 
one  of  a  series  of  recommendations  is,  for  distinctness, 
paragraphed  separately,  and  in  a  letter  in  which  each 
item  of  an  order  for  goods  is  marked  out  by  separate 
paragraphing.  Quotations,  moreover,  are  usually  para- 
graphed separately  to  distinguish  them  from  the  sur- 
rounding text.  Besides  these  special  uses  as  a  visual 
device  paragraphing  serves  the  twofold  purpose  of  break- 

53 


54    COMPOSITION  OF  TECHNICAL  PAPERS 

ing  up  a  gompositional  mass,  which  without  it  would  be 
hard  to  read,  and  of  showing  the  reader  where  the 
different  thought  divisions  of  the  composition  occur. 
It  is  this  last  kind  of  paragraphing  which  will  be  con- 
sidered in  the  present  chapter.  In  a  study  of  the  para- 
graph as  a  division  of  the  whole  composition  two  questions 
immediately  arise  for  consideration:  first,  where  are  the 
paragraph  divisions  to  occur?  and,  second,  what  shall  be 
the  internal  organization  of  the  paragraph?  These 
will  be  taken  up  in  the  order  named. 

Paragraph  Division 

Paragraphing  has,  it  was  pointed  out,  a  twofold 
purpose:  first,  by  breaking  up  the  compositional  mass 
into  parts,  it  serves  to  make  the  composition  easier  to 
read;  second,  it  serves  to  assist  the  reader  in  perceiving 
the  underlying  plan  of  the  whole  composition.  The 
first  of  these  purposes  affects  the  absolute  length  of  the 
paragraph;  the  second  affects  the  content. 

An  examination  of  the  paragraphs  in  a  number  of 
expositions  of  different  types  will  reveal  considerable 
variety  in  paragraph  length.  A  comparison,  for  example, 
of  the  paragraphing  of  an  editorial  in  a  newspaper 
which  caters  to  ''the  people"  with  that  of  an  article 
in  The  Atlantic  Monthly  will  show  that  the  paragraphs 
of  the  editorial  are,  for  obvious  reasons,  much  shorter 
than  those  of  the  Atlantic  article.  Between  the  para- 
graphs of  expositions  which  present  less  contrast  there  is, 
however,  less  difference  to  be  noted,  and  an  extended 
study  of  paragraph  lengths  will  show  that  convention 
has  set  an  approximate  limit  in  both  directions  to  the 
length  of  the  paragraph.  It  is  a  part  of  the  duty  of  the 
paragrapher   to   conform   with   this   convention,   which 


THE  PARAGRAPH  55 

represents,  after  all,  the  best  practice  for  the  reader,  by 
preventing  paragraphs  that  are  either  so  short  as  to  be 
choppy  or  so  long  as  to  be  tiresome. 

An  investigation  of  paragraph  length  in  a  number  of 
well-paragraphed  technical  articles  revealed  the  fact 
that  in  ordinary  technical  writing  the  paragraph  very 
seldom  runs  over  four  hundred  words  or  under  one  hun- 
dred. A  paragraph  over  four  hundred  words  seems  too 
long;  in  most  places  where  such  paragraphs  occur  they 
may  be  broken  up  into  two  or  more  paragraphs  without 
defeating  the  second  aim  of  paragraphing,  the  indication 
of  thought  division.  Conversely,  paragraphs  which  run 
under  one  hundred  words  seem  choppy  and  may  in  most 
cases  be  easily  combined  with  other  paragraphs.  The 
average  length  is  about  one  hundred  and  seventy-five 
words.  In  ordinary  technical  exposition,  then,  four  hun- 
dred words,  or  thereabouts,  should  represent  the  upper 
limit  of  paragraph  length,  and  seldom  should  the  para- 
graph run  under  one  hundred  words.  It  should  be  re- 
membered, of  course,  that  these  lengths  relate  only  to 
paragraphs  which  occur  in  expository  writing  as  distinct 
parts  or  units  of  the  whole  composition  and  not  to 
paragraphs  of  the  other  types  mentioned. 

The  question  of  the  absolute  length  of  the  paragraph, 
a  matter  determined  largely  by  conventional  usage,  is 
not  as  important  as  that  of  its  content.  Paragraph 
dividing  is  not  a  matter  of  measuring  off  parts  having  an 
average  length  of  one  hundred  and  seventy-five  or  two 
hundred  words;  the  mere  indention  of  the  line  marks  the 
paragraph  but  does  not  make  it.  If  the  reader  is  to  feel 
that  the  paragraph  is  of  assistance  to  him  in  his  under- 
standing of  the  organization  of  the  whole  composition, 
the  writer  must  make  the  indentions  only  when  he  has 


56    COMPOSITION  OF  TECHNICAL  PAPERS 

completed  a  definite  phase  of  the  subject;  in  other  words, 
each  paragraph  must  take  up  and  develop  one  distinct 
part  of  the  whole;  it  must  be  just  as  unified  within  its 
own  limits  as  the  whole  composition  is  within  larger 
limits.  The  chief  difficulty  in  paragraphing  is  in  deter- 
mining just  how  large  a  division  of  the  whole  or  how  small 
shall  be  included  within  the  paragraph  limits.  No 
fixed  rule  can  be  given;  the  writer  should,  however,  in 
all  cases  avoid  choppy  paragraphing  by  selecting  as  his 
paragraph  subject  such  a  part  of  the  whole  idea  as  is 
capable  of  some  development,  and  he  should  avoid  over- 
flowing his  paragraphs  by  being  careful  not  to  put  into 
them  two  or  more  phases  which  could  more  conveniently 
and  easily  be  developed  in  separate  paragraphs.  Be- 
tween the  writer's  working  outline  and  the  paragraph 
division  there  is  no  fixed  relation.  In  a  short  exposition 
it  is  possible  for  each  major  division  of  the  subject, 
as  shown  by  the  outline,  to  be  developed  within  the  limits 
of  a  single  paragraph.  In  a  long  exposition,  on  the  other 
hand,  the  major  division  may  need  several  paragraphs 
for  its  complete  development,  each  one  taking  up  a  sub- 
division of  it.  The  idea,  therefore,  that  it  is  possible  to 
determine  in  each  case  from  the  working  outline  the  exact 
number  of  paragraphs  necessary  is  erroneous. 

The  relation  between  the  outHne  and  the  problem  of 
paragraphing  and  the  principle  of  unity  or  singleness  of 
subject  in  the  paragraph  can  best  be  illustrated  by  a 
concrete  example.  Let  it  be  assumed  that  the  same 
writer  has  been  asked  to  write  two  expositions  on  the 
subject  How  Photographs  Are  Made,  the  first  a  very  brief 
explanation  of  nine  hundred  words  or  thereabouts  and 
the  second  a  short  pamphlet.  His  outlines  and  the 
corresponding  paragraphs  might  be  as  follows: 


THE  PARAGRAPH  57 

Exposition  I  .           Exposition  II 

(900  words)  (30,000  words) 

Introduction:  Chapter    i.     Definition   of 

A.  Definition     of    photo-  photography  and  explana- 
graphy.  tion  of  the  chemical  prin- 

B.  Description  of  the  cam-  ciples  involved  (15  para- 
era  graphs). 

( I  paragraph  of  1 50  words).  Chapter  2.     Description  of 

the  camera  (20 paragraphs). 
Body: 

I.  Making  the  exposure  (i  Chapter    3.     Making    the 

paragraph  of  200  words).  exposure  (25  paragraphs). 

II.  Making  the  negative  (i  Chapter    4.     Making     the 

paragraph  of  300  words),  negative  (40  paragraphs). 

III.  Making    the    print     (i  Chapter    5.     Printing     (35 

paragraph  of  250  words).  paragraphs). 

It  will  be  observed  that  the  outline  of  Exposition  I  is 
in  relation  to  the  length  of  the  article  fuller  than  the 
outline  of  Exposition  II,  but  that  the  major  divisions  of 
the  two  outlines  correspond. 

Paragraph  4  of  Exposition  I  might  be  written  as 
follows: 

I.  Even  more  entertaining  than  making  the  negatives 
is  the  last  stage,  that  of  making  the  prints.  2.  The 
chemical  principle  involved  here  is  the  same  as  in  the 
making  of  negatives,  the  action  of  light  on  a  sensitized 
surface;  in  printing,  however,  the  sensitized  surface  is 
not  on  glass  or  celluloid  but  on  paper,  and  the  result  is 
not  a  negative  but  a  positive  image.  3.  Printing  may  be 
done  in  a  variety  of  ways  and  on  a  variety  of  papers;  the 
process  of  printing  by  artificial  light  on  "developing 
papers"  will  be  here  explained.  4.  The  baths  are 
prepared  exactly  as  in  the  process  of  developing  plates 


58    COMPOSITION  OF  TECHNICAL  PAPERS 

by  hand.  5.  When  all  are  ready,  the  light  is  dimmed, 
the  negative  is  put  into  a  "printing  frame,"  which 
resembles  a  small  picture  frame,  the  sensitized  side  of  a 
sheet  of  the  printing  paper  is  placed  next  to  the  negative, 
the  back  of  the  frame  is  clipped  on,  and  all  is  ready  for 
the  "exposure."  6.  This  consists  in  allowing  the  light 
to  shine  through  the  negative  upon  the  sensitized  paper 
for  a  length  of  time  dependent  upon  various  conditions. 
7.  After  exposure  the  paper  is  removed  from  the  frame 
and  immersed  in  the  developing  bath  until  the  images 
appear  clearly.  8.  After  being  rinsed  in  water,  the  print 
is  thrown  into  the  "hypo,"  or  fixing  bath,  where  it  is 
allowed  to  soak  thoroughly.  9.  Next  it  is  washed  for 
at  least  half  an  hour  in  running  water,  or  in  several 
changes  of  water.  10.  Drying  face  down  on  a  cloth 
surface  or  between  blotters  completes  the  process. 

An  analysis  of  this  ten-sentence  paragraph  shows  it  to 
be  made  up  of  the  following  divisions: 

Sentence  i.  Link  with  the  preceding  division,  and 
announcement  of  the  new  paragraph  subject. 

2.  Statement  of  the  principle  involved  in  printing. 

3.  Announcement  of  the  limitations  of  the  paragraph 
subject. 

4.  Preparing  the  chemical  baths. 

5.  Loading  the  printing  frame. 

6.  Making  the  exposure. 

7.  Developing  the  print. 

8.  Fixing  the  print. 

9.  Washing  the  print. 

10.  Drying  the  print. 

Sentences  i  to  3  here  together  form  the  introduction 
of  the  paragraph;  sentences  4  to  10  together  form  the 
body.     Each  sentence  in  this  latter  group  contributes 


THE  PARAGRAPH  59 

toward  the  development  of  the  paragraph  subject, 
making  the  print;  each  one  is,  however,  so  manifestly 
slight  in  itself  that  it  would  be  absurd  to  think  of  it  in 
its  present  form  as  long  enough  for  a  separate  paragraph; 
and  to  break  the  paragraph  up,  therefore,  into  as  many 
subdivisions  as  there  are  subjects  announced  in  the 
sentences  would  be  to  paragraph  very  badly.  When,  on 
the  other  hand,  the  total  length  of  the  exposition  is  con- 
sidered and  the  consequent  amount  of  development 
possible  for  this  one  thought  division,  it  will  be  seen  that 
the  making  of  the  print  does  very  well  as  the  subject  of 
a  single  paragraph.  It  should  be  noted,  incidentally, 
that  the  paragraph  is  only  slightly  longer  than  average. 
In  Exposition  II,  it  will  be  observed,  paragraph  4  of 
Exposition  I  has  been  expanded  into  a  35-paragraph 
chapter.  Here  each  one  of  the  sentences  of  paragraph 
4  has  been  so  developed  as  to  become  no  longer  a  mere 
tributary  to  the  development  of  the  paragraph  thought, 
but  an  independent  subject  of  one  or  more  paragraphs, 
having  in  its  turn  subordinate  details  which  develop  it 
Sentence  6,  for  example,  making  the  exposure,  which  in 
Exposition  I  is  a  mere  announcement  of  a  process  detail, 
becomes  the  subject  of  a  considerable  exposition,  in 
which  such  matters  as  printing  frames,  intensity  of  light, 
relation  of  density  of  negative  to  length  of  exposure, 
"dodging,"  the  making  of  enlarged  prints,  etc.,  are  given 
full  consideration,  each,  perhaps,  as  the  subject  of  an 
individual  paragraph  or  of  a  group  of  paragraphs.  Thus 
the  subject  of  paragraph  4  becomes  in  Exppsition  II  the 
subject  of  an  entire  chapter,  and  each  detail,  too  slight 
and  undeveloped  in  the  first  exposition  to  be  regarded  as 
a  subject  for  an  entire  paragraph,  expands  into  a  para- 
graph or  even  becomes  the  subject  of  a  considerable 


6o    COMPOSITION  OF  TECHNICAL  PAPERS 

group  of  paragraphs,  one  of  the  major  divisions  of  the 
chapter. 

The  foregoing  explanation  illustrates  the  problem  of 
paragraph  division  as  it  applies  to  explanations  of 
processes.  In  descriptive-exposition  the  principles  are 
identical,  the  difference  being  only  in  the  type  of  subject 
matter  involved.  This  may  be  simply  illustrated  from 
paragraph  i  of  Exposition  I  and  chapter  2  of  Exposition 
II.  The  description  of  the  camera  in  paragraph  i 
would,  of  course,  be  very  short,  a  mere  outline.  The 
camera  might  here  be  described  as  follows: 

*  *  *  The  instrument  used  in  the  ordinary  processes 
of  photography  is  the  camera.  Cameras  are  of  various 
types,  but  all  are  operated  on  the  same  essential  princi- 
ples, and  each  consists  of  a  light-tight  box  with  an 
aperture  at  one  end  that  is  fitted,  excepting  in  *' pin- 
hole" cameras,  with  a  lens  to  produce  a  sharp  definition 
of  the  projected  image  and  a  shutter  to  control  the 
admission  of  light.     *  *  * 

This  brief  outline,  which  could  not  very  well  be  much 
longer  in  the  short  exposition  of  which  it  is  a  part,  would 
become  in  Exposition  II  an  entire  chapter  in  which  each 
detail  would  be  considerably  expanded.  The  lens,  for 
example,  merely  mentioned  in  Exposition  I,  might  become 
the  subject  of  a  long  explanation,  with  a  paragraph  or 
more  devoted  to  each  important  type  of  lens. 

Expositions  in  which  the  subject-matter  is  more 
abstract  and  the  order  of  arrangement  more  arbitrary 
than  in  descriptive-expositions  and  expositions  of  pro- 
cesses are  governed  by  the  same  essential  principles  of 
paragraph  division.  In  such  expositions,  however,  the 
subject  of  the  paragraph  is  not  a  part  of  a  machine 
described  or  a  detailed  step  of  a  process,  but,  usually,  a 


THE  PARAGRAPH  6i 

single  "point"  or  division  of  the  whole  thought.  An 
exposition  of  about  a  thousand  words,  for  example,  on 
Requirements  of  a  Good  Electrical  Testing  Laboratory 
might  have  five  paragraph  subjects  as  follows: 

Paragraph  i.  Introductory:     The    value    of    a    good 
testing  room. 

2.  Good  location. 

3.  Adequate  equipment. 

4.  Efficient  management. 

5.  Good  permanent  records. 

Each  paragraph  subject  here  is  big  enough  for  develop- 
ment within  the  limits  of  a  paragraph  of  the  average 
length.  In  a  much  longer  article  on  the  same  subject 
the  details  of  each  paragraph  would  expand  into  full 
paragraph  subjects. 

An  attempt  has  been  made  in  the  foregoing  explana- 
tion to  demonstrate  that  good  paragraphing  comes  from 
an  observance  of  the  conventional  usage  which  has  set 
the  approximate  limits  to  the  actual  length  of  the  para- 
graph, and  even  more  from  the  development  within  the 
limits  of  the  paragraph  of  a  single  part  or  phase  of  the 
whole  composition.  It  follows  that  any  intrusion  into 
a  paragraph  of  a  detail  which  does  not  contribute  to  the 
development  of  the  central  thought  or  paragraph  subject 
is  a  palpable  violation  of  the  second  and  more  important 
of  these  guiding  principles.  Such  a  violation  can  come 
only  from  careless  planning  of  the  whole  or  from  a  failure 
to  guard  the  integrity  of  the  paragraph.  The  follow- 
ing careless  paragraph  from  a  description  of  a  waterwheel 
shows  the  tendency  to  put  together  into  a  single  para- 
graph material  which  should  be  paragraphed  separately: 

"The  cups  around  the  circumference  of  the  wheel  are 
oval;  the  reason  for  this  form  of  cup  is  that  it  results  in 


62     COMPOSITION  OF  TECHNICAL  PAPERS 

more  pressure  than  can  be  obtained  from  any  other  form. 
Just  why  this  should  be  so  can  be  seen  from  the  sketch, 
which  shows  that  the  impinging  stream  transmits  two 
forces  on  each  half  cup,  the  first  created  when  the  water 
hits  the  cup,  and  the  second  when  it  leaves  the  cup. 
The  cups  are  so  arranged  that  the  stream  will  always 
strike  a  cup  in  any  position  of  the  wheel  and  secure  a 
maximum  leverage  for  such  a  position.  The  wheel  is 
mounted  on  a  shaft  on  one  end  of  which  is  a  pulley.  The 
head  of  water  at  the  nozzle  used  for  these  wheels  varies  from 
about  twenty  feet  to  as  high  as  can  he  obtained^  and  the 
horsepower  developed  ranges  between  one  and  one-hundred.''^ 
The  subject  of  this  paragraph  is  clearly  the  water-cups, 
and  the  statements  in  the  italicized  sentences  relating  to 
the  mounting  of  the  wheel,  the  head  of  water  used,  and 
the  horsepower  developed  have  no  business  here;  they 
are  misplaced  details  which  should  be  doing  duty  in  other 
paragraphs.  Similar  violations  of  the  unity  of  the  para- 
graph occur  in  any  paragraph  in  which  there  are  details 
that  do  not  belong  to  the  central  thought  or  paragraph 
subject. 

Internal  Organization  of  the  Paragraph 

The  handling  of  the  details  of  the  paragraph  in  such  a 
manner  that  they  develop  the  central  thought  clearly  is 
a  problem  partly  of  logical  arrangement  of  the  details, 
partly  of  making  their  relationship  immediately  evident 
to  the  reader  by  a  careful  indication  of  their  connection. 
There  is  no  universal  method  of  arrangement  to  be  fol- 
lowed in  organizing  a  paragraph;  the  plan  of  each  para- 
graph, like  the  plan  of  each  whole  composition,  is  to  a 
certain  extent  peculiar.     It  is  possible,  however,  to  give 


THE  PARAGRAPH  63 

general  suggestions  which  will  almost  always  assist  the 
writer  to  secure  a  clear  organization  of  his  paragraph 
material. 

An  analysis  of  any  well-written  expository  paragraph 
will  show  it  to  possess  a  central  thought  and  certain  de- 
tails which  serve  to  define  and  elucidate  the  central  idea 
and  enrich  it  in  its  meaning  or  application.  In  organiz- 
ing a  paragraph  it  is  usually  best  for  the  sake  of  definite- 
ness  and  clearness  to  indicate  the  subject  of  the  para- 
graph, the  central  thought,  definitely  at  the  beginning, 
either  in  the  first  sentence  or  very  soon  after  it.  Such 
an  initial  step  means  that  the  reader  knows  at  once  what 
phase  of  the  subject  he  is  about  to  take  up;  on  the  other 
hand,  not  to  make  such  a  definite  announcement  results 
in  the  reader's  receiving  a  very  vague  and  uncertain 
impression  of  the  central  idea.  This  announcement,  or, 
as  it  is  sometimes  called,  proposal  of  the  subject,  is  to 
the  paragraph  what  the  writer's  announcement  of  his 
whole  subject  in  his  general  introduction  is  to  his  whole 
composition;  its  omission  results  in  both  cases  in  the 
reader's  groping  for  a  central  thought,  for  a  container^, 
so  to  speak,  of  the  ideas  which  follow. 

In  certain  types  of  paragraph,  of  course,  it  is  desirable 
and  at  times  even  necessary  to  state  the  subject  of  the 
paragraph  last  instead  of  first.  This  is  true  of  all  para- 
graphs in  which  the  central  idea  would  be  unintelligible 
without  considerable  preliminary  development.  An 
abstract  proposition,  for  example,  might  mean  nothing 
whatever  to  a  reader  until  he  has  been  led  up  through 
a  careful  series  of  concrete  illustrations  to  understand  it. 
This  type  of  paragraph  does  not  occur,  however,  very 
frequently  in  ordinary  technical  composition;  in  the 
majority  of  cases  the  clearness  of  the  paragraph  is  best 


64    COMPOSITION  OF  TECHNICAL  PAPERS 

served  by  a  definite  indication  at  the  beginning  of  the 
subject  to  be  developed. 

Following  the  announcement  of  the  paragraph  subject 
there  may  be  some  necessary  definition  or  limitation  of 
it,  or  for  added  clearness  it  may  be  restated  in  another 
form.  This  part  of  a  paragraph  is  by  no  means  always 
essential.  It  is  most  likely  to  occur  in  exposition  of 
ideas  rather  than  in  exposition  of  concrete  facts. 

After  the  subject  announcement  and  subject  definition 
which  sometimes  follows  come  naturally  the  details 
which  develop  the  central  thought.  Such  details,  of 
course,  vary  widely  in  their  nature.  In  a  paragraph 
from  a  descriptive-exposition,  for  example,  where  the 
paragraph  subject  is,  let  us  say,  one  part  of  a  machine 
being  described,  the  details  will  give  the  appearance  of 
this  part,  its  mechanical  construction,  function,  relation 
to  parts  previously  described,  etc.  In  a  paragraph  from 
an  exposition  of  a  process,  where  the  paragraph  subject 
is,  perhaps,  a  minor  step  in  the  manufacture,  the  details 
will  naturally  explain  this  step  from  point  to  point  and 
possibly  give  its  relation  to  the  entire  process.  A  para- 
graph from  an  exposition  dealing  with  ideas  which  are 
more  abstract  will  have  its  central  thought  developed  by 
definition,  evidence,  citations  of  authority,  examples  and 
illustrations,  comparisons,  etc.,  in  almost  unending  vari- 
ety. No  principle  for  their  logical  arrangement  can  be 
given;  in  each  paragraph  the  writer  must  determine 
what  order  will  best  bring  out  the  central  thought  or 
paragraph  subject. 

In  descriptive-expositions  and  explanations  of  proc- 
esses the  paragraph  usually  ends  with  these  developing 
details.  In  expositions  dealing  with  more  abstract 
material,  however,  the  details  are  frequently  followed  by 


THE  PARAGRAPH  65 

other  material,  some  comment,  it  may  be,  on  a  proposi- 
tion which  the  paragraph  has  aimed  to  estabHsh,  or  a 
restatement  in  some  emphatic  form  of  the  idea  devel- 
oped. Just  when  it  is  necessary  or  advisable  to  add  this 
final  element  must  be  determined  for  each  individual 
paragraph. 

The  following  diagram  of  a  typical  paragraph  and 
summary  of  the  suggestions  given  for  paragraph  organi- 
zation may  help  to  make  the  principles  clearer.  The 
numbers  refer  not  to  sentences  but  to  elements  in  the 
paragraph.  The  arrangement  given  here,  as  has  been 
pointed  out,  is  by  no  means  universal;  it  is,  however,  in 
technical  writing  by  far  the  most  frequent. 

1.  Link  with  preceding  paragraph  or  division  (often 
combined  with  2.) 

2.  Announcement  of  the  paragraph  subject. 

3.  Details  developing  the  paragraph  subject  and  form- 
ing the  body  of  the  paragraph. 

4.  Occasional  comment  on  idea  developed. 
Solidity  and  compactness  of  the  paragraph  result  very 

largely  from  a  careful  attention  to  the  form  of  the  in- 
dividual sentences  and  a  careful  arrangement  of  all  the 
details.  These  qualities  result  also  very  largely  from  a 
deliberate  binding  together  of  the  sentences  by  various 
transition  devices.  The  importance  to  the  clearness  of 
the  whole  composition  of  those  sentences  which  serve  to 
bind  the  different  paragraphs  together  was  pointed  out 
in  the  preceding  chapter.  Within  the  paragraph,  too, 
there  are  similar  links  between  sentences  and  groups  of 
sentences  which  serve  to  indicate  the  interrelationship 
of  parts  and  to  make  the  whole  paragraph  solid  and  com- 
pact. Such  devices  may  consist  of  a  phrase  in  which  the 
idea  of  the  preceding  sentence  is  picked  up  and  carried 


66    COMPOSITION  OF  TECHNICAL  PAPERS 

on,  or  of  a  word  indicating  that  one  sentence  contains 
an  idea  that  is  in  sequence  with  that  of  a  preceding 
sentence  {first,  secondly,  next,  afterward,  then,  etc.),  is 
added  to  it  {moreover,  again,  also,  furthermore),  contrasts 
with  it  {however,  nevertheless,  in  spite  of,  yet),  is  the  result 
of  it  {therefore,  consequently,  accordingly),  or  stands  in 
some  other  relation  to  it.  Often,  especially  when  in  the 
development  of  a  central  thought  a  number  of  similar 
ideas  are  introduced,  mere  similarity  of  sentence  struc- 
ture will  indicate  that  the  sentences  have  the  same  func- 
tion in  the  paragraph,  and  no  specific  transition  device 
need  be  used.  In  all  cases  care  should  be  taken  to  use 
the  device  which  best  indicates  the  thought  relationship 
between  the  sentences  concerned,  and  to  avoid  falling 
into  the  habit  of  monotonously  using  one  transition 
device  to  the  exclusion  of  others.  The  lack  of  clearness 
which  may  result  from  their  complete  exclusion  is  well 
illustrated  in  the  following  paragraph.  This  paragraph 
possesses  unity,  since  it  deals  with  but  one  phase  of  a 
larger  subject,  but  so  carelessly  have  the  details  been 
handled  that  the  impression  is  indistinct,  and  the  ideas 
seem  out  of  focus. 

I.  The  first  important  consideration  in  electrification 
is,  can  the  same  or  better  service  be  obtained  with  electric 
locomotives  than  with  steam  locomotives?  2.  It  has 
been  shown  in  nearly  every  case  where  it  has  been  tried 
that  electrification  improves  the  service  considerably. 
3.  Electric  locomotives  are  in  their  infancy  as  compared 
with  steam  locomotives,  and  yet  the  former  have  reached 
seemingly  the  highest  point  of  perfection.  4.  At  present 
the  best  types  are  operated  at  92  per  cent,  efficiency  from 
third  rail  to  rim  of  drivers,  maintained  in  original  operat- 
ing condition  at  a  cost  of  3  cents  per  mile,  and  required 


THE  PARAGRAPH  67 

to  be  inspected  only  after  1,200  miles  of  operation.  5. 
Steam  locomotives  are  not  nearly  as  efficient,  and  have 
to  be  continually  overhauled  and  repaired,  and  will  stand 
much  improvement.  6.  With  the  use  of  the  superheaters, 
stokers,  etc.,  their  eflftciency  is  being  gradually  increased. 
7.  The  time  used  by  the  steam  locomotive  in  taking  on 
coal  and  water  and  changing  engines  is  done  away  with 
by  the  use  of  the  electric  locomotives,  since  the  latter 
may  be  run  continuously.  8.  A  considerable  loss  of 
coal  is  involved  when  each  locomotive  is  run  independ- 
ently of  the  others,  as  the  steam  locomotive.  9.  Experi- 
ment has  shown  that  about  10  per  cent,  of  the  amount  of 
coal  consumed  is  used  in  the  actual  moving  of  the  trains. 
10.  The  rest  is  used  in  firing  up,  standing  on  the  sidings 
and  in  the  round-house,  coasting  down  grades,  for  bank- 
ing, etc.  1 1 .  In  the  electric  locomotive  the  electric  brake 
may  be  used,  thus  saving  overheating  of  the  car  wheels 
caused  by  the  friction  of  the  brake  shoes  upon  them  when 
the  automatic  air  is  used. 

Many  of  the  sentences  in  the  paragraph  are  absurdly 
faulty  in  construction;  we  will,  however,  confine  our 
attention  to  the  paragraph  as  a  whole.  The  paragraph 
thought  is  apparently  "Electric  locomotives  are  superior 
to  steam  locomotives."  A  very  close  scrutiny  will 
show  that  the  writer  has  three  reasons  in  support  of  this 
proposition:  Electric  locomotives  are  superior  to  steam 
locomotives  because  (i)  their  operating  efficiency  is 
higher,  (2)  they  are  more  economical  in  (a)  time  and  {h) 
coal,  and  (3)  they  use  the  electric  instead  of  the  air  brake. 
These  three  "points"  have,  however,  been  run  together 
with  no  attempt  at  marking  the  separation.  Moreover, 
many  of  the  sentences  have  been  written  with  no  ap- 
parent regard  for  the  development  of  the  central  idea; 


68    COMPOSITION  OF  TECHNICAL  PAPERS 

sentence  6,  for  example,  is  as  it  stands  a  clear  argument 
for  the  steam  locomotive.  In  the  following  rewriting 
of  the  paragraph  an  attempt  has  been  made  to  bring  out 
the  central  thought  more  clearly. 

I.  When  a  railroad  company  considers  the  electrifica- 
tion of  its  road,  the  first  and  most  important  question  to 
arise  is:  Do  electric  locomotives  give  better  service  than 
steam  locomotives?  2.  The  evidence  shows  that  in 
nearly  every  case  where  electrification  has  been  tried, 
they  do  give  better  service.  3.  In  the  first  place,  in 
spite  of  the  fact  that  they  are  still  in  their  infancy  as 
compared  with  steam  locomotives,  they  are  much  more 
efficient  in  operation.  4.  The  best  types  are  now 
operated  at  92  per  cent,  efficiency  from  third  rail  to  rim 
of  drivers;  they  are,  moreover,  maintained  in  their 
original  operating  condition  at  a  cost  of  only  3  cents  per 
mile;  and  they  need  inspection  only  after  1,200  miles  of 
operation.  5.  Steam  locomotives,  on  the  other  hand,  in 
spite  of  the  fact  that  superheaters,  stokers,  and  other 
mechanical  devices  are  gradually  increasing  their 
efficiency,  are  not  nearly  as  efficient;  moreover,  they  have 
to  be  continually  overhauled  and  repaired;  and  they  need 
very  frequent  inspection.  6.  In  economy,  as  well  as  in 
mechanical  efficiency,  the  electric  locomotive  is  superior 
to  the  steam  locomotive.  7.  The  electric  locomotive  is  a 
time  saver  in  that  it  does  not,  like  the  steam  locomotive, 
require  coaling,  taking  on  of  water,  and  changing  of 
engines.  8.  It  is  economical  also  in  fuel  saved.  9. 
The  steam  locomotive,  because  unlike  the  electric  loco- 
motive it  is  an  independent  generator  of  energy,  actually 
uses  in  moving  its  trains  only  about  10  per  cent,  of  the 
total  coal  which  it  consumes;  the  rest  is  used  in  firing  up 
and  banking,  and  while  the  locomotive  is  standing  idle  on 


THE  PARAGRAPH  69 

sidings  or  in  the  round-house,  or  is  coasting  down 
grades.  10.  The  electric  locomotive  has  another  ad- 
vantage in  its  use  of  the  electric  brake  instead  of  the 
automatic  air  brake,  since  the  latter  results  in  frequent 
overheating  of  the  car- wheel  rims  from  the  friction  caused 
by  the  brake  shoes.  11.  Under  actual  operating  condi- 
tions, therefore,  there  can  be  little  doubt  of  the  decided 
superiority  of  the  electric  locomotive. 

An  examination  of  the  following  paragraphs  with  the 
brief  analysis  following  each  will  fix  more  firmly  in  mind 
the  principles  of  paragraph  construction  which  have  been 
explained.  The  paragraphs  have  been  purposely  selected 
from  the  usual  types  of  technical  exposition,  and  present 
no  particular  peculiarities  of  form.  A  further  analysis 
of  paragraphs  selected  at  random  from  the  examples  of 
technical  composition  in  Part  II  of  this  book  will  be 
found  a  valuable  exercise  in  studying  the  paragraph. 

I.  I.  The  main  piece  of  apparatus,  remarkable  alike 
for  the  simplicity  of  its  construction  and  the  range  of  its 
performance,  is  the  annunciator.  2.  In  the  earher  forms 
of  the  alarm,  the  indications  were  made  by  means  of  a 
simple  switchboard  provided  with  buttons  bearing  the 
names  of  the  apartments  protected.  3.  When  an  alarm 
sounded,  the  depression  of  each  of  these  buttons  in  turn 
until  the  bell  ceased  ringing  was  necessary  to  determine 
its  locality.  4.  This  is  still  quite  largely  used  as  it  is 
cheaper  than  the  more  perfect  annunciator  which  tells 
at  a  glance  where  the  disturbance  in  the  circuit  is.  5. 
In  shape  and  size  this  latter  instrument  resembles  an 
ordinary  mantel-clock.  6.  The  indications  are  given  by 
devices  on  the  face,  which  vary  with  different  makers. 
7.  In  one  form  they  are  made  by  arrows,  which  lie  hori- 


70    COMPOSITION  OF  TECHNICAL  PAPERS 

zontal  when  in  normal  position,  and  point  to  the  names 
of  the  apartments  printed  above  them  when  indicating. 
8.  In  another  form  cards  drop  down  in  front  of  apertures 
arranged  in  rows  on  the  face,  and  in  still  another  the 
name  and  number  of  a  room  are  uncovered  by  a  falling 
piece  when  an  alarm  is  sounded.  9.  The  needle  instru- 
ment is  shown  in  Fig.  i.  10.  Once  made,  the  indications 
remain  until  the  parts  are  restored  by  some  one.  11.  A 
small  switch  at  one  side  completes  or  opens  the  circuit 
through  the  instrument,  and  one  on  the  other  side  con- 
trols the  connection  with  the  bell.  12.  A  row  of  studs 
at  the  base  of  the  apparatus  allows  any  opening  to  be 
disconnected  that  may  be  desired.  13.  Aside  from  its 
giving  an  alarm  when  an  attempt  is  made  to  enter  a 
building,  the  annunciator  has  an  important  use  in 
showing  when  a  place  is  properly  closed.  14.  If  any 
window  or  door  has  been  forgotten,  it  will  infallibly 
point  it  out.  15.  In  large  business  houses  where  there 
are  many  openings  this  feature  is  of  the  greatest  value. 
16.  By  disconnecting  the  bell,  this  test  can  be  made  a 
silent  one. 

Sentence  i.  Subject  of  the  paragraph,  the  annun- 
ciator, and  announcement  of  points  to  be  emphasized: 
(i)  the  simplicity  of  construction;  and  (2)  the  range  of 
performance. 

2-4.  Description  and  operation  of  early  types. 

5-12.  Description  and  operation  of  various  later 
types. 

13-16.  An  additional  use  of  the  annunciator  illustrating 
the  "range  of  its  performance." 

II.  I.  The  pendulum  consists  of  a  12.2-inch  (30.9- 
centimeter)  United  States  Army  mortar,  weighing  31,600 


THE  PARAGRAPH  71 

pounds  (14,333  kilos),  which  was  supphed  by  the  Bureau 
of  Ordnance  of  the  War  Department.  2.  The  mortar 
rests  in  a  stirrup  made  of  two  machine-steel  rods  ij^ 
inches  (3.8  centimeters  )in  diameter,  each  bent  into  a  U 
shape.  3.  The  ends  of  each  of  these  rods  are  passed 
through  two  cast-steel  saddles,  which  fit  over  a  steel 
supporting  beam.  4.  The  supporting  beam  is  8  by  4 
inches  (20.3  by  10.2  centimeters)  in  section  and  87 
inches  (221  centimeters)  long.  5.  This  beam  is  pro- 
vided with  two  nickel-steel  (3  per  cent,  nickel)  knife 
edges,  which  are  countersunk  into  its  lower  face  near 
each  end  (see  Fig.  i).  6.  The  knife  edges  rest  on  bearing 
plates  measuring  2  by  8  by  10  inches  (5.08  by  20.3  by 
25.4  centimeters). 

Sentence  i.  Paragraph  subject,  description  of  the 
pendulum,  and  general  statement  that  a  mortar  was 
used. 

2-6.  Details  of  construction  of  the  pendulum  support. 

III.  I.  The  testing  gallery  (Plates  III  and  IV)  was  a 
rectangular  boiler-iron  box,  18  by  18  by  24  inches,  pro- 
vided with  a  glass  door,  two  observation  windows,  and 
a  circular  opening  13  inches  in  diameter  at  the  top  of 
the  box  to  relieve  the  pressure  developed  by  an  explosion. 

2.  This  opening  was  covered  by  a  sheet  of  paper  coated 
with  paraffin  and  held  in  place  by  a  heavy  iron  ring. 

3.  The  electrical  connections  were  brought  into  the 
gallery  through  gas-tight  bushings.  4.  A  sliding  rod  for 
breaking  the  lamps  penetrated  the  side  of  the  gallery 
through  a  gas-tight  steel  bushing. 

Sentence  i.  Paragraph  subject,  general  description  of 
the  testing  gallery;  general  appearance  and  parts. 
2-4.  Additional  details  of  construction. 


72     COMPOSITION  OF  TECHNICAL  PAPERS 

IV.  I.  The  actual  process  of  developing  a  film  is  fairly 
simple.  2.  First  the  film  is  unrolled  and  detached  from 
its  light-proof  cover.  3.  Then  it  is  immersed  quickly 
in  the  developer  solution.  4.  While  in  the  solution,  the 
film  is '  kept  constantly  in  motion  to  prevent  uneven 
development.  5.  After  a  few  moments  the  picture 
begins  to  show  up.  6.  As  soon  as  the  development  has 
gone  far  enough  so  that  the  outline  of  the  picture  may  be 
seen  clearly  on  the  reverse  side  of  the  film,  it  is  removed 
from  the  developer  and  rinsed  quickly  in  water.  7. 
Next  it  is  placed  in  the  soda  or  "hypo"  solution,  where  it 
remains  until  the  milk-like  deposit  on  the  reverse  side 
has  been  dissolved  off,  and  the  film  appears  perfectly 
transparent  throughout.  8.  The  film  is  then  washed 
thoroughly  in  running  water  for  at  least  30  minutes, 
and  is  finally  hung  up  to  dry.  9.  After  drying  the  film 
is  ready  for  printing. 

Sentence  i:  Paragraph  subject,  process  of  developing 
a  film. 

2-9:  Detailed  steps  in  the  process. 

V.  Method  of  Conducting  Test 


I.  The  head  of  the  cylinder  is  now  removed.  2.  One 
leg  of  a  No.  7  electric  detonator  is  fastened  to  the  wire 
that  passes  through  the  insulated  plug  on  the  upper 
segment  of  the  cyUnder,  and  the  other  leg  is  grounded 
to  the  gage  through  the  iron  support  with  which  it  is  in 
contact.  3.  The  detonator  is  inserted  and  secured  in 
the  cartridge,  and  the  cartridge  laid  upon  the  wire  sup- 
port. 4.  The  head  of  the  cylinder  is .  then  replaced. 
5.  The  cylinder  is  now  exhausted  until  the  internal  pres- 


THE  PARAGRAPH  73 

sure  equals  10  millimeters  of  mercury,  and  the  motor 
which  operates  the  drum  is  set  in  revolution.  6.  When 
everything  is  ready,  the  charge  is  fired  by  an  electric 
firing  device,  and  the  indicator  record  is  taken. 

Paragraph  subject,  method  of  making  an  explosion 
test,  is  announced  by  the  sub-title  printed  above  the 
paragraph. 

Sentences  1-6:  Detailed  steps  in  the  process. 

VI.  I.  Trolley  wires  in  mines  present  a  most  fruitful 
source  of  electric  shock.  2.  Trolley  wires  are  neces- 
sarily bare  conductors;  they  may  extend  for  long  dis- 
tances throughout  a  mine,  and  often  they  must  be  in- 
stalled less  than  a  man's  height  above  the  track  rail 
which  is  used  as  part  of  the  return  circuit.  3.  A  low 
trolley  wire  is  especially  dangerous  in  places  where  men 
must  work  in  making  up  trips  of  cars,  as  at  partings  where 
loaded  trips  are  brought  out  to  the  foot  of  a  rope-haulage 
system.  4.  Under  such  circumstances  both  the  loaded 
and  the  empty  trips  are  in  the  parting  at  the  same  time, 
and  m^-nipulation  is  required  to  make  up  the  loaded  trip 
to  be  taken  out  on  the  rope  and  to  split  up  the  empty 
trip  to  be  taken  in  by  the  various  locomotives.  5.  It 
is  often  desirable  to  do  this  work  rapidly,  and  if  the 
trolley  wires  are  lower  than  a  man's  head,  the  chance  for 
shock  is  considerable.  6.  Even  if  the  men  are  familiar 
with  the  conditions,  their  attention,  while  hurrying  to 
get  the  trips  away  from  the  parting,  can  not  be  con- 
stantly on  the  trolley  wire. 

Sentence  i:  Paragraph  subject,  the  dangers  from 
trolley  wires  in  mines. 

2:  General  dangers. 

3-6:  Especial  dangers  of  low  trolley  wires. 


74    COMPOSITION  OF  TECHNICAL  PAPERS 

VIT.  I.  Several  tests  were  next  made  to  determine 
whether  fuse  could  be  made  to  "flash"  under  ordinary 
conditions  of  temperature  and  pressure,  solely  by  con- 
stricting some  points  in  its  length.  2.  Pieces  of  fuse  of 
definite  length  were  taken,  and  by  means  of  pliers  were 
held  tightly  at  a  number  of  points  in  such  a  way  as  to 
prevent  the  escape  of  gas  beyond  the  constriction  pro- 
duced by  the  jaws  of  the  pHers.  3.  In  these  experi- 
ments a  somewhat  increased  rate  of  burning  was  noted 
(82  seconds  per  meter,  or  25  seconds  per  foot,  as  against 
a  normal  rate  of  burning  of  92.5  seconds  per  meter  or 
28.8  seconds  per  foot),  but  in  no  case  did  the  fuse  flash 
entirely  through  or  even  for  a  considerable  distance. 
4.  There  was  always  a  sharp  report  caused  by  the  gases 
suddenly  bursting  through  the  side  of  the  fuse,  but  this 
appeared  to  be  simply  a  local  phenomenon.  5.  The 
break  produced  in  the  fuse  provided  at  once  an  exit  for 
the  gases  sufficient  to  prevent  any  further  increase  in 
the  rate  of  burning.  6.  When  constrictions  were  placed 
every  2  or  3  centimeters  along  a  piece  of  fuse,  the  rate 
of  burning  was  not  increased  more  than  about  10  per 
cent. 

Sentence  i:  Paragraph  subject,  tests  made  of  fuse 
constricted  at  arbitrary  points  in  its  length. 

2:  Method  employed. 

3-6:  Various  results  observed. 

VIII.  I.  The  general  behavior  of  the  lamps  in  the  tests 
of  series  i,  i-A,  i-B,  i-C,  and  i-D  was  the  same.  2. 
With  three  exceptions,  the  filaments  of  the  standard 
lamps  were  broken  when  the  bulbs  were  smashed,  but  the 
miniature-lamp  filaments  usually  remained  intact.  3. 
Ignitions,  when  they  occurred  in  the  tests  of  standard 


THE  PARAGRAPH  75 

lamps,  seemed  to  take  place  almost  simultaneously  with 
the  blow  of  the  breaking  hammer,  but  in  some  of  the 
miniature-lamp  tests  the  ignition  of  gas  was  delayed 
until  several  seconds  had  elapsed  after  the  bulb  had  been 
broken.  4.  In  most  tests  the  bulb  was  practically  de- 
stroyed by  the  blow.  5.  In  a  few  tests  the  breaking  rod 
merely  made  a  hole  in  the  side  of  the  bulb. 

Sentence  i:  Paragraph  subject,  general  behavior  of 
lamps  under  certain  tests. 

2-5:  Details  relating  to  breaking  of  filaments  (2), 
ignitions  (3),  and  damage  done  to  bulb  (4  and  5). 

IX.  I.  The  word  "liquid"  as  used  in  this  discussion 
denotes  all  the  forms  of  combustible  between  gaseous 
and  solid;  that  is,  such  substances  as  in  a  strict  physical 
sense  are  not  gases  or  solids.  2.  For  example,  if  we  pour 
some  coal  tar  in  its  viscous  semiliquid  form  into  a  hot 
coal  fire,  a  very  dense  brown  "smoke"  will  issue  from  it. 
3.  We  know  that  this  smoke  is  not  gas;  it  is  also  hard  for 
us  to  beUeve  that  all  this  smoke  would  consist  of  tiny, 
angular  pieces  of  solid  carbon.  4.  It  is  perhaps  easier  to 
think  that  at  least  a  part  of  the  smoke  is  composed  of 
minute  globules  of  the  tar  which  have  been  boiled  off, 
somewhat  like  the  visible  "steam"  coming  out  of  boiling 
water.  5.  For  lack  of  better  expression,  we  say  that  the 
combustible  in  the  globules  is  in  "liquid"  form. 

Sentence  i:  Paragraph  subject,  definition  of  the 
word  "liquid." 

2-5:  Specific  example  to  illustrate  the  use  of  the 
word. 

X.  I.  In  my  opinion  a  patent  covering  the  invention 
should  not  be  applied  for  until  the  third  stage  is  about 
80  per  cent,  completed,  and  the  experimenter  knows  with 


76    COMPOSITION  OF  TECHNICAL  PAPERS 

reasonable  certainty  that  his  process  will  work  and  that 
his  apparatus  has  permanent  value.  2.  A  patent  drawn 
at  this  period  is  sure  to  be  of  real  worth.  3.  As  the  idea 
has  passed  through  the  three  preliminary  stages,  it  has 
undergone  modifications  and  changes.  4.  Now,  however, 
it  is  a  well-formulated,  definite,  practical  fact,  a  thing  to 
which  the  inventor  is  properly  entitled  to  protection. 
5.  Such  a  patent  is  almost  always  obtainable  and  seldom 
vulnerable.  6.  The  invention  has  been  developed  logi- 
cally and  as  rapidly  as  systematic  work  would  permit; 
therefore  it  is  unlikely  that  others  who  started  later 
have  overtaken  the  experimenter  in  this  particular  field. 
7.  Ideas  hastily  formulated  and  lightly  patented  seldom 
are  sufficiently  complete  to  be  of  value;  consequently, 
interference  from  them  is  not  to  be  greatly  feared, 
especially  if  the  statement  of  conception,  made  and  re- 
corded at  the  end  of  the  first  stage,  is  available.  8. 
Before  the  patent  is  issued,  the  third  stage  will  have 
been  completed,  the  design  of  the  apparatus  determined, 
its  efficiency  and  durability  demonstrated,  and  the  con- 
struction of  the  Semi-commercial  Plant  begun. 

Sentence  i:  Introductory  to  announcement  of  para- 
graph subject. 

2 :  Paragraph  subject,  a  proposition  to  be  established. 

3-8:  Points  in  support  of  the  paragraph  proposition. 


CHAPTER  V 
THE  SENTENCE 

Introduction 

The  ability  to  construct  a  genuinely  good  sentence  is 
much  more  rare  than  the  ability  to  organize  a  whole 
composition  or  to  plan  a  paragraph.  The  reason  for 
this  is  not  difficult  to  understand.  The  larger  the  unit, 
the  more  deliberately  it  may  be  dealt  with;  the  smaller 
the  unit,  the  more  difficult  it  is  to  manipulate.  A 
writer  who  may  have  considerable  skill  in  arranging 
the  divisions  of  a  long  exposition  and  even  in  planning  a 
paragraph  may  still  write  very  poor  sentences  because 
he  has  no  fundamental  knowledge  of  sentence  structure 
or  because  he  has  not  the  art,  and  it  is  an  art,  of  so  group- 
ing the  details  of  his  sentence  that  the  result  will  be  an 
effective  expression  of  the  idea  which  he  wishes  to  con- 
vey. The  sentence  is  usually  so  small  a  unit  that  it 
slips  away  from  him;  twist  his  idea  how  he  may,  he  still 
finds  the  clear  and  vigorous  expression  of  it  baffling. 
Even  when  he  has  learned  to  avoid  the  pitfalls  of  sentence 
construction  which  is  positively  incorrect,  he  still  may 
write  sentences  which  are  slovenly  and  weak,  for  the 
problem  of  good  sentence-making  is  the  problem  not 
only  of  writing  correctly  but  also  of  writing  effectively. 
The  price  which  must  be  paid  for  good  sentences  is  con- 
stant vigilance  and  painstaking  revision.  No  amount 
of  drill  in  correcting  the  bad  sentences  of  others  can  take 

77 


78    COMPOSITION  OF  TECHNICAL  PAPERS 

the  place  of  care  in  constructing  and  correcting  one's 
own  sentences.  Such  drill  can,  however,  assist  the 
writer  to  a  better  understanding  of  sentence  construc- 
tion; it  can  help  him  to  get  a  better  grip  on  his  own 
ideas  and  to  manipulate  the  elements  of  his  sentences 
with  more  assurance  and  power. 

In  revising  his  exposition  a  writer  should  test,  his 
sentences  from  two  points  of  view:  he  should  make  cer- 
tain, first,  that  each  sentence  is  correctly  constructed 
and  is  as  clear  and  vigorous  as  he  can  possibly  make  it; 
and  he  should  make  certain,  second,  that  each  sentence 
is  doing  its  share  in  the  development  of  the  paragraph 
idea.  This  second  test  will  determine,  for  example, 
whether  a  sentence  is  properly  linked  to  other  sentences, 
whether,  perhaps,  it  is  parallel  in  form  with  a  preceding 
sentence  which  contains  a  coordinate  idea,  whether,  in 
brief,  it  runs  smoothly  into  the  paragraph  mold  or  is  a 
misfit.  The  necessity  of  considering  each  sentence  in 
connection  with  related  sentences  will  appear  from  the 
following  sentence  group.  At  the  left  the  ideas  appear 
incorrectly  divided  into  sentences  and  with  the  cHmax 
of  the  group,  contained  in  the  phrase  "portable  oxyhy- 
drogen  outfit,"  obscured  and  unemphatic;  in  the  recon- 
struction at  the  right  an  attempt  has  been  made  to 
correct  these  defects. 

Inefective  Improved 

In  the  erection  of  almost  In  the  erection  of  almost 

every  large  steel  building  or  every  large  steel  building  or 

bridge,   it  is  necessary  that  bridge   it   is    necessary   to 

several  of  the  steel  parts  or  alter   several   of   the   steel 

members   be   altered   before  parts    or    members    before 

they  can  be  fitted  together  they  can  be  fitted  together 

to   make  up   the  structure.  to  make  up  the  structure; 


THE  SENTENCE  79 

Sometimes  a  member  must  be  sometimes  they  must  be  cut 
cut  and  sometimes  two  parts  into  different  shapes,  and 
must  be  welded  together,  and  sometimes  two  of  them 
a  portable  oxyhydrogen  out-  must  be  welded  together, 
fit  is  generally  used  to  do  this  To  do  this  work  use  is  gen- 
work,  erally  made  of  a  portable 

oxyhydrogen  outfit. 

Most  of  these  questions,  however,  although  they  affect 
radically  the  construction  of  any  connected  group  of 
sentences,  belong  really  to  the  study  of  the  paragraph. 
This  chapter  on  the  sentence  will,  accordingly,  be  con- 
cerned with  a  study  of  the  individual  sentence,  its  con- 
struction and  the  defects  to  which  it  is  liable.  The 
plan  to  be  followed  will  be  to  give  first  a  brief  explanation 
of  the  anatomy  of  the  sentence,  and  then  to  take  up  in 
succession  a  number  of  the  principles  governing  the  con- 
struction of  sentences  ^  which  are  clear,  well-balanced, 
vigorous,  and  otherwise  effective.  The  chapter  does 
not  aim  to  be  a  complete  treatise  on  the  subject;  it  aims 
merely  to  give  a  general  understanding  of  the  essential 
framework  of  the  sentence  and  of  some  of  the  avoidable 
defects  and  errors  in  construction  which  are  most  likely 
to  result  in  obscure  and  weak  expression  of  ideas. 

Grammatical  Structure  of  the  Sentence 

To  define  the  sentence  is  not  easy.  The  old  defini- 
tion of  the  sentence  as  the  "verbal  expression  of  a  single 
complete  thought"  is  vague  inasmuch  as  the  phrase 
"single  complete  thought"  is  not  clear;  a  sentence,  as 
every  reader  knows,  may  properly  be  very  short,  only 
a  word  or  two,  or  it  may  just  as  properly  be  very  long  and 
contain  not  a  single  thought  but  a  great  many  related 
ones.     It  is  better,  perhaps,  to  ask  what  elements  are 


8o    COMPOSITION  OF  TECHNICAL  PAPERS 

absolutely  essential  to  make  a  group  of  words  a  true 
sentence.  To  this  question  there  is  a  definite  answer: 
every  sentence  must  consist  of  at  least  one  independent 
subject  and  predicate,  that  is,  of  a  substantive — noun, 
pronoun,  or  word-group  used  for  a  noun — and  a  verb  which 
asserts  something  of  the  substantive  and  which  may  or 
may  not  have  an  object.  Such  a  subject-predicate  com- 
bination, or  predication,  as  it  is  called,  is  said  to  be  inde- 
pendent when  it  can  stand  unsupported  by  any  other 
predication;  it  is  said  to  be  dependent  when  it  needs  the 
support  of  another  predication.  Excepting  for  such 
expressions  as  "Fire,"  "Help,"  "Run,"  etc.,  where  the 
idea  appears  in  a  shortened  form,  every  complete  sentence 
must  contain  at  least  one  independent  predication. 
Examples  will  make  this  clearer. 

It  is  obvious  that  "The  boiler  exploded,"  short  as  it 
is,  is  a  true  sentence  since  it  consists  of  a  subject,  "  boiler," 
and  a  predicate,  "exploded,"  and  is  independent  of  any 
other  word-group.  It  is  equally  obvious  that  in  the 
word-group,  "The  boiler  exploded  painfully  injuring 
the  fireman,"  the  words  "painfully  injuring  the  fireman" 
can  not,  standing  alone,  be  a  sentence  since  they  contain 
no  subject  and  since  the  verb  is  not  in  the  form  in  which 
it  can  be  used  in  a  predicate.  Similarly,  in  the  word- 
group,  "When  the  boiler  exploded,  the  fireman  was 
painfully  injured,"  the  first  part,  up  to  the  comma,  can 
not  by  any  possibility  be  made  into  a  separate  sentence 
since,  although  it  has  a  subject,  "boiler,"  and  predicate, 
"exploded,"  it  is  clearly  dependent  upon  the  second  word- 
group,  and  by  our  definition  a  sentence,  to  be  a  sentence, 
must  be  able  to  stand  alone. 

Diagrammatically  the  brief  sentence  which  we  have 
been  examining  may  be  represented  as  follows: 


THE  SENTENCE 


8i 


(Subject) 
boiler 


(Predicate) 
exploded 


Excepting  for  such  shortened  constructions  as  have  been 
referred  to,  "Fire,"  "Help,"  "Run,"  etc.,  this  sentence 
is  about  as  short  as  a  sentence  can  be  made.  Often,  as 
has  ah*eady  been  indicated,  the  predicate  is  expanded  by 
an  object  which  receives  the  action  of  the  verb;  this 
invariably  occurs  with  the  so-called  transitive  verbs, 
which  require  an  object  to  complete  their  meaning. 
Diagrammatically  a  sentence  with  subject  and  predicate 
consisting  of  both  verb  and  object  may  be  represented 
thus: 

(Predicate) 


(Subject) 
explosion 


(verb) 
injured 


(object) 
fireman 


For  the  sake  of  simplicity,  however,  we  will  make  use  in 
the  explanation  which  follows  of  the  simpler  form  of  a 
subject  and  a  predicate  consisting  only  of  the  verb. 

In  the  simple  sentence  as  we  now  have  it  something 
definite  is  affirmed  or  "predicated"  of  the  subject 
"boiler."  Now,  without  making  any  further  direct 
assertion  about  the  boiler,  we  may  add  indirectly  new 
ideas  concerning  it.  Similarly,  we  may  add  indirectly 
to  the  ideas  concerning  the  circumstances  under  which 
the  explosion  occurred.  For  example,  we  may  write, 
"The  new  boiler  exploded  suddenly.''^  In  this  sentence 
the  word  new  is  called  an  adjective  because  it  is  added  to 

6 


82     COMPOSITION  OF  TECHNICAL  PAPERS 


the  noun  which  it  qualifies;  the  word  suddenly  is  called  an 
adverb  because  it  is  added  to  the  verb  which  it  modifies. 
It  will  be  seen  that  our  expanded  sentence,  though  still 
short,  really  contains  three  ideas — no  longer  a  single  one: 
these  are  (i)  "The  boiler  exploded;"  (2)  "The  boiler 
was  new;"  (3)  "The  explosion  was  sudden."  Only  one 
of  these,  the  first,  is,  however,  basic;  the  others  are 
clearly  subordinate. 

But  it  is  not  only  single  words  which  may  be  added 
thus  indirectly  to  both  the  noun-subject  and  the  verb- 
predicate;  groups  of  words  may  also  become  a  part  of 
the  sentence.  For  example,  we  may  write,  ''The  new 
boiler  in  the  east  engine  room  exploded  suddenly  and 
entirely  without  warning.''  Diagrammatically  this  may 
be  presented  thus: 


(Subject) 
boiler 


(Predicate) 
exploded 


(In  this  diagram  and  in  those  which  come  later  the  expla- 
nation has  been  simplified  by  considering  the  modifying 
word-groups  as  wholes;  no  attempt  has  been  made,  that 
is,  to  indicate  the  relationships  of  words  in  any  modify- 
ing word-group  to  other  words  in  the  same  group.)  The 
word-groups  added  to  the  sentence  are  called  phrases; 
the  first,  because  it  modifies  a  substantive,  is  called  an 
adjective-phrase,  and  the  second,  because  it  modifies  a 


THE  SENTENCE 


83 


verb  is  called  an  adverb-phrase.  A  phrase  contains  no 
subject  and  predicate.  It  will  be  observed  that  more 
ideas  have  been  added  to  the  sentence,  but  that  it  still 
contains  only  one  predication  or  subject-predicate  com- 
bination. Such  a  sentence,  no  matter  how  many  qualify- 
ing single  words  and  phrases  it  may  have,  is  called  a 
simple  sentence. 

But  it  is  possible  to  add  to  the  sentence  not  only  adjec- 
tive- and  adverb-phrases  but  adjective-  and  adverb- 
clauses.  A  clause  is  a  word-group  which  contains  a 
subject  and  predicate;  when  it  is  used  to  modify  a 
substantive  or  a  verb,  that  is,  when  it  is  either  an  adjec- 
tive- or  an  adverb-clause,  it  is  said  to  be  dependent; 
when,  on  the  other  hand,  it  is  not  used  as  a  modifier  but 
can  stand  alone,  it  is  said  to  be  independent.  It  will  be 
noted  at  once  that  the  sentence  with  which  we  started, 
**The  boiler  exploded,"  is  an  independent  clause;  in 
this  case  it  happens  also  to  be  a  complete  sentence.  An 
adjective-  and  adverb-clause  added  to  our  growing  sen- 
tence might  make  it  read  as  follows:  "The  new  boiler 
in  the  east  engine  room,  which  was  purchased  only  last 
months  exploded  suddenly  and  entirely  without  warning 
while  the  fireman  was  out  of  the  room. "  Diagrammati- 
cally  this  may  be  represented  thus: 


(Subject) 
boiler 


(Predicate) 
exploded 


(Subject) 
which 


(Predicate) 
was  pur- 
chased only  \  %. 
last  month 


I  "U  (Subject) 
15  theengi- 
I  fi       neer 


(Predicate) 
was  out  of 
the  room 


84    COMPOSITION  OF  TECHNICAL  PAPERS 

It  will  be  seen  that  without  in  the  least  overburdening 
the  sentence  we  have  added  still  further  ideas  about  the 
engine  and  concerning  the  circumstances  attending  the 
accident.  It  will  be  seen,  too,  that  we  have  here  not 
one  predication,  or  subject-predicate  combination,  but 
threCj  the  original  independent  one,  "the  boiler  ex- 
ploded," an  adjective-  or  relative  clause,  as  it  is  often 
called,  "which  was  purchased  only  last  month,"  and 
an  adverb-clause,  "(while)  the  fireman  was  out  of  the 
room."  The  simple  sentence,  it  will  be  remembered, 
contained  only  one  clause;  we  have  here,  therefore,  a 
new  grammatical  type,  the  complex  sentence.  This  is 
the  name  given  to  a  sentence  which  contains  one  inde- 
pendent clause  and  one  or  more  dependent  clauses.  In 
a  complex  sentence  the  independent  clause  is  called  the 
principal  clause. 

There  remains  one  further  grammatical  type  of 
sentence  to  explain,  the  compound  sentence.  A  com- 
pound sentence  is  one  which  consists  of  two  or  more  inde- 
pendent clauses.  When  in  addition  to  these  independent 
clauses,  there  are  dependent  clauses,  the  sentence  is 
sometimes  called  a  compound-complex  sentence.  A 
further  expansion  of  the  sentence  with  which  we  have 
been  working  will  give  us  an  example  of  this  more  compli- 
cated type.  Thus  expanded,  the  sentence  might  read, 
"The  new  boiler  in  the  east  engine  room,  which  was 
purchased  only  last  month,  exploded  suddenly  and  en- 
tirely without  warning  while  the  fireman  was  out  of 
the  room,  and  since  the  accident,  the  plant  has  been  oper- 
cUed  only  with  the  greatest  difficulty.'^  Diagrammatically 
this  may  be  represented  as  shown  on  page  85.  The 
simple  original  statement,  "The  boiler  exploded,"  has 
been  very  greatly  expanded  with  words,  phrases,  and 


THE  SENTENCE 


8S 


(Subject) 
boiler 


(Predicate) 
exploded 


IP    (Subject) 
'  '^-      which 


(Predicate) 
was  pur- 
chased only 
last  month 


l  (Subject) 
1         the 
^    fireman 


(Predicate) 
was  out  of 
the  room 


(subject) 
plant 


(Predicate) 
has  been  operated 


clauses  modifying  both  the  original  noun-subject  and 
the  original  verb-predicate.  Finally  there  has  been 
added  an  independent  clause  which  is  connected  to  the 
original  independent  clause  only  by  a  coordinating  con- 
junction, "and,"  a  mere  coupling-pin  to  hold  the  two 
parts  together.  And  though  in  the  process  of  growth 
the  sentence  has  passed  from  simple  to  complex  and  from 
complex  to  compound,  the  central  thought  has  remained 
the  core  of  the  sentence,  made  equal  or  coordinate  in 
the  sentence  of  the  last  type  with  a  new  independent  idea; 
at  no  time  has  the  sentence  ceased  to  be  an  integer. 
By  the  process  of  expanding  a  single,  simple  subject- 


86    COMPOSITION  OF  TECHNICAL  PAPERS 

predicate  combination  we  have  come  to  some  realization 
of  what  a  sentence  is.  It  has  been  demonstrated  that  a 
combination  of  words  in  order  to  be  a  true  sentence  must 
have  at  least  one  independent  subject  and  predicate; 
it  may  be  very  simple  or  it  may  be  very  intricate  with  a 
number  of  modifying  words,  phrases,  and  clauses,  and 
even  with  independent  clauses  more  or  less  closely  asso- 
ciated with  it.  A  summary  of  what  has  been  said  about 
the  anatomy  of  the  sentence  and  a  review  of  the  defini- 
tions which  have  been  arrived  at  inductively  during  the 
course  of  the  preceding  explanation  may  serve  to  give  a 
clearer  understanding  of  sentence  structure. 

The  elements  which  may  enter  into  the  framework 
of  a  sentence  can  best  be  shown  in  a  simple  table: 


(Subject) 
Noun   or   pronoun   or 
phrase  or  clause  used 

as  a  noun 


verb 


(Predicate) 

object 

Noun  or  pronoun  or  phrase 

or  clause  used  as  a  noun 


Adjectival  elements: 

1.  Word  (adjective). 

2.  Adjective-phrase. 

3.  Adjective-clause. 


Adverbial  elements:  Adjectival  elements :- 

1.  Word  (adverb).  i.  Word  (adjective.) 

2.  Adverb-phrase.  2.  Adjective-phrase. 

3.  Adverb-clause.  3.  Adjective-clause. 


From  this  table  the  basic  elements  which  compose  a 
sentence  are  seen  to  be  single  words,  phrases,  and 
clauses.  Of  the  single  words  the  most  essential  are  the 
nouns  and  pronouns,  and  the  verbs;  modifying  the  sub- 
stantives are  the  adjectives;  modifying  the  verbs  are  the 
adverbs.  Other  single  words  which  play  a  part  in  the 
sentence  are  prepositions,  which  indicate  certain  relation- 
ships between  words,  conjunctions,  used  to  join  single 
words  or  word-groups,  and  interjections,  mere  exclama- 
tions  introduced   into    the   sentence    usuaUy    without 


TEE  SENTENCE  87 

grammatical  connection.  All  of  these  taken  together  are 
called  the  parts  of  speech. 

A  phrase  is  a  word-group  which  does  not  have  a  sub- 
ject and  predicate.  It  may  be  used  as  the  subject  of  a 
verb,  as  the  object  of  a  verb,  as  the  modifier  of  a  sub- 
stantive, verb,  or  adverb. 

A  clause  is  a  word-group  which  contains  a  subject  and 
predicate.  Like  the  phrase  it  may  be  used  as  subject 
or  object  of  a  verb  or  as  an  adjectival  or  adverbial  modi- 
fier. It  may  be  either  independent,  in  which  case  it  can 
stand  alone  and  may  even  constitute  a  complete  simple 
sentence,  or  dependent,  in  which  case  it  must  be  connected 
with  an  independent  clause  and  cannot  be  a  sentence. 

The  grammatical  classification  of  sentences  into  simple, 
complex,  and  compound  depends  upon  the  number  of 
clauses  within  the  sentence  and  the  mutual  dependence 
or  independence  of  these  clauses.  A  sentence  which 
contains  a  single  clause,  which  will,  of  course,  be  inde- 
pendent, is  called  a  simple  sentence  no  matter  how  many 
modifying  single  words  or  phrases  it  may  have.  A 
sentence  which  contains  a  single  independent  clause  and 
one  or  more  dependent  clauses  is  called  a  complex  sentence. 
Finally,  a  sentence  which  contains  two  or  more  independent 
clauses  is  called  a  compound  sentence. 

In  the  foregoing  exposition  of  the  anatomy  of  the 
sentence  not  everything  that  might  be  said  about  the 
grammatical  structure  of  the  sentence  has,  of  course, 
been  said.  An  attempt  has  been  made  merely  to  give 
such  a  general  understanding  of  the  essential  framework 
of  the  sentence  as  is  absolutely  necessary  for  an  intelli- 
gent consideration  of  the  rhetorical  principles  of  good 
sentence-making.  It  should  be  remembered  that,  gram- 
matically speaking,  any  sentence  is  theoretically  sus- 


88     COMPOSITION  OF  TECHNICAL  PAPERS 

ceptible  of  indefinite  expansion.  Not  only  nouns  and 
pronouns  but  phrases  and  clauses  may  be  made  the  sub- 
jects and  objects  of  verbs.  Moreover,  any  substantive 
and  any  verb  which  is  part  of  a  qualifying  phrase  or 
clause  may  itself  be  modified  by  additional  words, 
phrases,  and  clauses.  To  realize  this  and  to  have  at  all 
times  a  grip  upon  the  essential  structure  of  one's  sen- 
tence is  fundamental  in  good  sentence-making.  With 
the  foregoing  explanation  of  the  grammatical  structure 
of  the  sentence  as  a  basis,  we  are  the  better  prepared, 
then,  to  turn  to  the  principles  which  underlie  the  con- 
struction of  sentences  which  are  not  only  correct  but 
clear  and  vigorous. 

Punctuation 

Punctuation  is  the  art  of  indicating  by  a  system  of 
marks  or  points  the  relationships  of  the  elements  in 
written  discourse.  Without  its  help  the  reader  would 
often  misunderstand  the  relationship  of  one  thought  to 
another.  How  necessary  in  some  cases  it  may  be  will 
appear  from  the  following  two  sentences,  which  are,  it 
will  be  observed,  identical  excepting  for  the  punctuation: 

The  student  who  believes  "The  student  who  believes 
that  punctuation  is  unneces-  that  punctuation  is  unneces- 
sary says  the  teacher  of  punc-  sary,"  says  the  teacher  of 
tuation  is  a  fool.  punctuation,  "is  a  fool." 

Now  it  does  not  often  happen  that  the  mere  punctuating 
of  a  sentence  will  so  completely  change  the  meaning;  it 
happens  very  often,  however,  that  mispunctuation,  or 
the  failure  to  punctuate  at  all,  results  in  ambiguity  or 
general  obscurity.  The  misplacing  or  omission  of  a 
single  comma  in  legal  documents  has  more  than  once  led 
to  differences  of  opinion  and  costly  litigation.     It  be- 


TEE  SENTENCE  89 

hooves  the  writer,  therefore,  to  make  the  best  possible 
use  of  this  device  for  making  his  ideas  clear.  Modern 
practice  is  opposed  to  over-punctuation;  but  modern 
practice  does  not  sanction  the  inclusion  or  omission  of  a 
punctuation  mark  where  such  misuse  or  neglect  would 
confuse  the  reader. 

Inasmuch  as  punctuation  aims,  on  the  grammatical 
side  at  least,  to  make  clear  certain  relationships  between 
sentences  and  parts  of  sentences,  the  subject  of  punctua- 
tion is  properly  a  corollary  to  that  of  the  grammatical 
structure  of  the  sentence.  The  chief  difficulties  in  punc- 
tuation occur  in  connection  with  the  use  of  the  period, 
comma,  and  semicolon;  the  proper  employment,  there- 
fore, of  these  points  or  stops  will  be  stressed.  It  should 
be  remembered  that  punctuation  is  not  an  exact  and 
fixed  science;  although  there  is  often  a  general  agreement 
upon  certain  of  the  more  fundamental  usages,  authorities 
disagree  in  minor  practices.  It  is  recommended,  ac- 
cordingly, that  every  writer  follow  some  standard 
authority;  if  he  does  this,  he  will  certainly  not  be  far 
from  right  in  practice,  and — what  is  perhaps  as  import- 
ant— his  usage  of  punctuation  marks  will  be  consistent 
in  all  his  writing.  ♦ 

The  Period,  Colon,  Semicolon,  and  Comma 

I.  At  the  end  of  a  complete  independent  predication, 
which  is  simply  assertive  or  declarative  {i.e.,  which  is  not 
a  question  or  an  exclamation),  and  which  is  not  joined 
to  a  following  independent  predication  by  a  simple 
coordinating  conjunction  {and,  hut,  for,  or),  use  a  period, 
colon,  or  semicolon. 

{a)  Use  a  colon  in  such  cases  only  when  the  predica- 


90    COMPOSITION  OF  TECHNICAL  PAPERS 

tion  directly  introduces  an  explanation,  list,  or  quotation 
which  immediately  follows. 

Right, — The  apparatus  should  be  set  up  as  follows: 

First,  clamp  the  flask  in  a  position  a  few  inches 

above  the  table;  next,  etc. 
Right. — The  President  of  the  association  introduced 

the  speaker  with  the  following  words:  ''Ladies 

and  gentlemen,"  etc. 
Right. — Upon  the  table  lay  the  following  articles:  A 

piece  of  glass  tubing,  a  Bunsen  burner,  etc. 

(b)  Use  a  period  at  the  end  of  such  a  predication 
when  it  is  felt  that  the  idea  contained  in  the  predication 
should  be  separated  rather  decidedly  from  the  idea 
following,  or  when  it  is  desired  to  emphasize  it  strongly. 

Right, — This  method  of  testing  is  based  on  measuring 
the  amount  of  heat  transferred  to  the  cooling 
water  from  the  condensed  steam.  It  is  ex- 
tremely inaccurate  and  unreliable,  and  it  can 
give  but  an  approximate  idea  of  the  quantity 
of  steam  being  condensed. 

Right. — The  results  of  the  experiment  are  shown  by 
the  comparative  curves  (Fig.  8).  From  these 
curves  it  will  be  seen  that  the  first  method  is 
productive  of  a  much  higher  degree  of  effi- 
ciency than  the  second. 

Right. — There  is  a  popular  notion  that  the  presence 
of  a  small  amount  of  lime  in  water  used  for 
the  generation  of  steam  is  of  no  consequence. 
This  I  most  emphatically  deny. 

(c)  Use  the  semicolon  at  the  end  of  such  a  predication 
when  it  is  felt  that  the  idea  contained  in  the  predica- 
tion is  more  immediately  connected  with  what  follows 
than  the  use  of  the  period  would  indicate. 


THE  SENTENCE  91 

Right. — The  steam  piping  connecting  the  boilers  and 
turbine  must  be  disconnected  from  all  other 
piping,  and  all  openings  must  be  blanked  off; 
valves  must  not  be  relied  on. 
Right. — There  is  only  one  method  by  which  such  boys 
can  be  properly  trained;  this  is  the  apprentice 
system. 
Right. — Such  a  practice  is  certainly  not  safe;  on  the 
contrary,  I  believe  it  to  be  highly  dangerous. 
Right. — This  new  method  of  electroplating  is  highly 
efficient ;  therefore  it  deserves  more  widespread 
use. 
{d)  The  comma  is  an  interior  mark  of  punctuation  and 
should  not  he  used  at  the  end  of  a  complete  independent 
predication  which  is  not  joined  to  a  following  predication 
by  a  simple  conjunction. 

Wrong. — The   submerging  of  coal  will  eliminate  all 
elements  which  contribute  toward  the  initial 
temperatures,  whether  or  not  such  submerg- 
ing is  industrially  practicable  in  any  given 
case  must  be  determined  by  experiment. 
Right. — The  submerging  of   coal  will   eliminate  all 
elements  which  contribute  toward  the  initial 
temperatures.     Whether    or   not   such    sub- 
merging is  industrially  practicable  in  any  given 
case  must  be  determined  by  experiment. 
Wrong. — Be  sure  in  all  cases  to  be  accurate  in  your 
measurements,     whatever    you     do,     don't 
guess. 
Right. — Be  sure  in  all  cases  to  be  accurate  in  your 
measurements;     whatever    you    do,     don't 
guess. 
Wrong. — It  usually  happens  that  such  practices  are 


92     COMPOSITION  OF  TECHNICAL  PAPERS 

not  permitted,  however,  they  are  sometimes 
allowed  under  certain  restrictions. 
Right. — It  usually  happens  that  such  practices  are 
not  permitted;  however,  they  are  sometimes 
allowed  under  certain  restrictions. 
Wrong. — "The  element  contained  in  this  flask  looks 
innocent  enough,"  said  the  lecturer,  "it  is, 
nevertheless,    one    of    the    most    dangerous 
explosives  known." 
Right. — "The  element  contained  in  this  flask  looks 
innocent  enough,"  said  the  lecturer;  "it  is, 
nevertheless,    one    of    the    most    dangerous 
explosives  known." 
2.  Between  coordinate  clauses  {i.e.,  clauses  which  are 
the  same  in  construction)  joined  by  a  simple  conjunction, 
use  a  comma  or  semicolon. 

(a)  When  the  clauses  are  fairly  short  and  simple  in 
construction,  use  a  comma. 

Right. — The  patient  is  turned  on  his  face,  and  the 

bearer  steps  astride  his  body. 
Right. — After  the  lantern  had  been  adjusted,  and  the 

lecturer  had  signified  his  readiness  to  begin, 

the  chairman  stepped  to  the  front  of  the 

platform. 

(b)  When  the  clauses  are  long  and  complex,  or  when 
a  sharp  separation  is  desired  between  them,  it  is  better 
to  use  a  semicolon. 

Right. — The  engineer  from  New  York  City  who 
addressed  the  seniors  yesterday  afternoon 
on  the  subject  of  Electrification  of  Steam 
Railways  was,  it  seems  to  me,  not  only 
thoroughly  acquainted  with  his  subject,  but 
successful  as  well  in  making  himself  clear 


THE  SENTENCE  93 

to   an   audience   of   inexperienced  students; 
but  the  man  from  Boston  who  addressed 
the  juniors  this  morning  on  the  same  subject 
very   evidently   did   not   have   so   wide   an 
acquaintance  with  his  subject,  nor  was  his 
presentation  so  clear. 
Right. — To  be  successful  in  one^s  profession  is  cer- 
tainly much  to  be  desired;  but  no  one  can 
reasonably   expect   that   success   will   come 
without   long,    unremitting,    heart-breaking 
toil. 
Right. — He  that  is  slow  to  anger  is  better  than  the 
mighty;  and  he  that  ruleth  his  spirit  than  he 
that  taketh  a  city. 

3.  An  adverb-clause  which  precedes  its  principal 
clause  should  be  set  off  by  a  comma.  When  the  adverb- 
clause  follows  the  principal  clause,  no  comma  is  ordinarily 
needed. 

Right, — After  all  has  been  said,  the  cheapest  motor 
V  in  the  long  run  is  the  one  which  costs  least  to 

operate. 
Right. — When  you  are  ready  to  leave,  please  turn  out 

the  light. 
Right. — The  man  in  the  stern  started  the  engine  as 

the  boat  was  pushed  from  the  pier. 

4.  (a)  Set  off  by  commas  any  phrase  or  clause  which 
modifies  a  preceding  substantive,  but  which  is  felt  to  be 
added  to  the  substantive  rather  than  to  be  an  integral 
part  of  it.     Such  constructions  are  called  non-restrictive. 

Right. — This  planer,  standing  in  the  worst  possible  posi- 
tion for  the  operator,  is,  nevertheless,  easier  to 
operate  than  any  other  planer  in  the  shop. 

Right. — ^The  machine  at  your  right,  which  has  been  in 


94     COMPOSITION  OF  TECHNICAL  PAPERS 

constant  use  for  nearly  ten  years,  is  about  to  be 
replaced  by  a  more  modern  one. 
{h)  Do  not   set   off   by  commas  a   phrase  or  clause 
which  is  felt  to  be  an  intimate  part  of  the  preceding  sub- 
stantive which  it  modifies.     Such  constructions  are  called 
restrictive. 

Right. — A  phrase  fitting  closely  to  its  substantive  is  said 

to  be  restrictive. 
Right. — A  clause  which  can  not  he  easily  detached  from 
the  substantive  which  it  modifies  should  not  be 
set  off  by  commas. 

5.  Use  the  comma  regularly  to  set  off  parenthetic 
words  and  phrases,  excepting  where  the  parenthetic  word 
or  phrase  is  introduced  so  suddenly  or  is  so  distinct  from 
the  context  that  the  dash  or  parenthesis  marks  would 
be  better. 

Right. — It  is  not  to  be  supposed,  of  course,  that  so 
small  an  instrument  will  do  all  the  work  of  a 
larger  one. 

Right. — ^Any  such  action  would,  however,  be  followed 
by  his  immediate  dismissal. 

6.  A  mere  subordinate  sentence  element  should  not  be 
capitalized  and  punctuated  as  though  it  were  an  inde- 
pendent sentence. 

Wrong. — In  one  operation  this  wonderful  machine 
stacks  and  binds  the  papers.  Thus,  in  reality, 
doing  the  work  of  two  machines. 
Right. — In  one  operation  this  wonderful  machine 
stacks  and  binds  the  papers,  thus,  in  reality, 
doing  the  work  of  two  machines. 

Wrong. — In  case  of  a  wreck  it  is  the.  engineer  who  is 
often  to  blame.  Whereas  the  fireman  sel- 
dom has  any  share  in  the  accident. 


THE  SENTENCE  95 

Right. — In  case  of  a  wreck  it  is  the  engineer  who  is 
often  to  blame,  whereas  the  fireman  seldom 
has  any  share  in  the  accident. 
Wrong. — Three  men  operate  the  contrivance.  One  as 
driver  and  two  as  his  assistants. 
Right. — Three  men  operate  the  contrivance,  one  as 
a  driver  and  two  as  his  assistants. 

Question  Mark,  Dash,  Parenthesis  Marks, 

Quotation  Marks,  Apostrophe, 

AND  Hyphen 

7.  Use  the  question  mark  after  a  direct  question  but 
not  after  an  indirect  question. 

Right. — He  asked  me  why  this  work  had  not  yet  been 

completed. 
Right, — Why  has  this  work  not  yet  been  completed? 

8.  Use  the  dash  to  indicate  an  abrupt  break  in  the 
thought. 

Right, — "Now,"  asked  the  professor,  as  he  picked  up 
his  watch,  "are  there  any  questions  which 
any  members  of  the  class  would — " 
"What  time  is  it,  professor?"  interrupted  a 
voice  from  the  back  row. 

Right. — I  believe  that  you  are  wrong  and  that — but 
just  a  minute;  would  you  mind  repeating  your 
statement? 

9.  Use  parenthesis  marks  to  enclose  parenthetic  words 
and  phrases.  Do  not  use  the  marks  where  a  pair  of 
commas  will  serve. 

Right. — It  was  just  about  this  date  (May  13,  191 2) 
that  the  city  began  to  consider  the  matter  of 
a  smoke  ordinance. 


96    COMPOSITION  OF  TECHNICAL  PAPERS 

Right. — The  tungsten  lamps  (everybody  will  remem- 
ber their  fragility)  were  exceedingly  difficult 
to  handle  in  testing. 

Right. — The  price  to  be  paid  for  the  concrete  "con- 
struction work  on  the  bridge  shall  not  exceed 
eight  thousand,  five  hundred  dollars  ($8,500). 

10.  Use  quotation  marks  to  enclose  direct  quotations 
but  not  indirect  quotations.  Only  words  actually 
quoted  should  be  enclosed. 

Wrong. — He  said  ''that  the  failure  of  the  bridge  was 

due  to  faulty  design," 
Right. — ''The  failure  of  the  bridge,"  said  the  lecturer, 

"was  due  to  faulty  design." 
Wrong. — He  was  of  the  opinion,  to  give  his  exact  words, 

"that    such    an    error    could    not    possibly 

happen  again." 
Right. — He  is  of  the  opinion,  to  give  his  exact  words, 

that  "such  an  error  can  not  possibly  happen 

again." 

11.  Use  the  apostrophe  with  possessives  (excepting  the 
possessive  adjectives  hers^  its,  ours,  yours,  and  theirs), 
and  to  indicate  the  omission  of  a  letter  or  of  letters  in  a 
contracted  word. 

Right. — The  fireman's  shovel;  the  superintendents' 
offices;  Charles's  bicycle;  can't,  hasn't,  don't, 
etc. 

12.  For  the  use  of  the  hyphen  it  is  difficult  to  give  any 
specific  rules.  "The  practice  of  lexicographers,  authors, 
and  printers  is  so  various  in  this  matter,"  says  Webster's 
Dictionary,  "  that  in  a  multitude  of  instances  it  is  hyper- 
critical or  whimsical  to  pronounce  dogmatically  that 
either  the  hyphened  or  unhyphened  form  is  the  only 
correct  one."    To  secure  consistency  in  individual  prac- 


THE  SENTENCE  97 

tice  it  is  well,  therefore,  to  adopt  and  follow  closely  some 
standard  authority,  learning  to  employ  readily  a  list  of 
words  (such,  for  example,  as  cast-iron  (adj.),  hydro- 
electric, safety  valve,  candlepower)  as  they  are  printed  in  a 
standard  dictionary  or  in  the  rules  governing  the  printing 
of  engineering  papers  adopted  by  a  high-class  technical 
magazine  or  by  an  engineering  institute.  In  this  way 
only  is  it  possible  to  secure  any  uniformity  of  practice. 

Good  and  Bad  Sentence  Construction 

The  difficulty  of  writing  a  genuinely  good  sentence  has 
already  been  pointed  out  at  the  beginning  of  the  chapter. 
Even  when  the  writer  has  an  acquaintance  with  the  gram- 
matical structure  of  the  sentence  and  can  make  proper 
use  of  the  auxiliary  device  of  punctuation  to  assist  in 
indicating  to  his  reader  the  relationship  of  sentence 
elements,  his  sentences  may  still  be  but  vague  and  weak 
carriers  of  his  ideas.  To  obtain  even  reasonable  clear- 
ness and  force  he  must  be  constantly  on  his  guard  to 
avoid  rhetorical  errors,  to  keep  from  writing  straggling 
and  badly  planned  sentences,  or  sentences  in  which  the 
relationship  of  parts  can  be  made  clear  by  no  amount  of 
care  in  punctuating.  The  following  pages  will  be  de- 
voted to  an  explanation  of  some  of  the  most  frequent  and 
insidious  faults  in  sentence  construction  and  the  methods 
of  avoiding  and  correcting  them.  In  studying  these 
errors  and  principles,  the  student  should  remember  that 
no  analysis  of  printed  sentences,  good  or  bad,  will  have 
much  effect  unless  such  study  results  in  self-criticism. 
Every  inexperienced  writer  should  be  a  perpetual  skeptic 
concerning  the  grammatical  and  rhetorical  soundness  of 
his  sentences  and  should  suspect  them  of  containing  all 
7 


98    COMPOSITION  OF  TECHNICAL  PAPERS 

the  mistakes  in  the  calendar  until  he  is  convinced  of  their 
genuine  clearness  and  force.  This  means  a  thorough 
familiarity  with  the  nature  of  the  mistakes  to  which  he  is 
liable  and  a  painstaking  revision  of  everything  which  he 
writes.  At  first  such  revision  will  be  slow;  with  practice 
it  will,  however,  become  more  rapid  and  more  accurate. 
It  is  the  aim  of  the  following  pages  to  give  the  student  the 
necessary  familiarity  with  some  of  the  errors  to  be 
avoided. 

The  sentences  used  to  illustrate  the  principles  discussed 
were,  with  a  few  easily  recognizable  exceptions,  taken 
from  engineering  magazines  and  pamphlets.  Inasmuch 
as  they  embody  various  degrees  of  ineffectiveness  in 
construction,  from  positive  badness  to  mere  flabbiness 
or  weakness  in  emphasis,  no  attempt  has  been  made  to 
label  each  one  with  a  descriptive  word  indicative  of  its 
structural  inadequacy.  When  two  sentences  are  printed 
side  by  side,  the  one  at  the  left,  labeled  Original,  is  meant 
to  be  an  illustration  of  the  particular  fault  or  weakness 
which  has  just  been  explained;  that  at  the  right,  labeled 
Revised,  embodies  an  attempt  to  improve  the  original 
sentence. 

I.  Sentence  Unity 

The  principle  of  sentence  unity  requires  that  every 
sentence  be  so  constructed  that  it  is  at  once  felt  to  be  a 
unit.  This  means  that  ideas  which  have  no  relationship 
should  not  be  forced  into  the  same  sentence;  it  means 
also  that  the  tendency  to  write  long,  rambling  sentences 
without  definite  plan  or  capacity  for  creating  a  unified 
impression  should  be  avoided.  To  be  unified  a  sentence 
need  not  be  short.  "Jesus  wept,"  the  shortest  verse  in 
the  Bible,  is,  of  course,  a  unit;  but  so  also  is  the  following 


THE  SENTENCE  99 

« 
beautiful    sentence    from    Ruskin's    Stones    of    Venice, 
planned  and  written  with  the  "sentence  feeling"  of  a 
genius : 

''Then  let  us  pass  farther  towards  the  north,  until  we 
see  the  orient  colors  change  gradually  into  a  vast  belt  of 
rainy  green,  where  the  pastures  of  Switzerland,  and  the 
poplar  valleys  of  France,  and  the  dark  forests  of  the 
Danube  and  Carpathians  stretch  from  the  mouths  of  the 
Loire  to  those  of  the  Volga,  seen  through  clefts  in  grey 
swirls  of  rain  cloud  and  flaky  veils  of  the  mist  of  the 
brooks,  spreading  low  along  the  pasture  lands;  and  then, 
farther  north  still,  to  see  the  earth  heave  into  mighty 
masses  of  leaden  rock  and  heathy  moor,  bordering  with 
a  broad  waste  of  gloomy  purple  that  belt  of  field  and 
wood,  and  splintering  into  irregular  and  grisly  islands 
amidst  the  northern  seas,  beaten  by  storm  and  chilled 
by  ice-drift,  and  tormented  by  furious  pulses  of  con- 
tending tide,  until  the  roots  of  the  last  forests  fall  from 
among  the  hill  ravines  and  the  hunger  of  the  north  wind 
bites  their  peaks  into  barrenness;  and,  at  last,  the  wall 
of  ice,  durable  like  iron,  sets,  deathlike,  its  white  teeth 
against  us  out  of  the  polar  twilight." 

This  is,  of  course,  a  ''literary"  sentence,  and  perhaps 
for  that  reason  it  is  unfair  to  contrast  it  with  the  fol- 
lowing loose-jointed,  rambling  sentence  in  which  no 
pretensions  to  literary  quality  are  made;  but  the  dif- 
ference between  the  two  is  startling  and  instructive:  • 

"With  my  aeroplane,  after  all  my  work  of  three  years, 
devoted  especially  to  improving  the  efficiency  of  the 
engine,  which  is,  after  all,  one  of  the  most  important 
matters  to  be  considered,  no  further  experiments  could 
be  made  because  of  the  lack  of  funds,  and  so  the  work 
had  to  be  suspended,  and  likewise  other  now  very  much 


loo    COMPOSITION  OF  TECHNICAL  PAPERS 


needed  experiments  concerning  automatic  balance  pro- 
pulsion and  so  forth,  can  not  be  made  for  the 
same  reason  respectively  because  there  is  no  experi- 
mental station  in  America  where  the  inventor  who  has 
been  working  for  some  time  on  his  device  can  get  his 
invention  tried  out  without  cost  to  the  inventor,  who 
as  a  rule  has  not  sufficient  funds  for  that  purpose  and 
becomes,  therefore,  discouraged  and  inclined  to  give  up 
all  further  effort,  whereas  a  place  for  trying  out  his  plans 
might  encourage  him  to  continue  his  work." 

The  method  of  correcting  a  sentence  which  lacks 
unity  is  either  to  reconstruct  it  upon  some  definite, 
orderly  plan  or — much  oftener — to  break  it  up  into  two 
or  more  sentences. 


Corrected 
Original 
A  process  of  "breaking 
down  "  is  now  necessary  to  re- 
duce the  mill  cake  to  a  fine 
meal,  so  that  it  can  receive 
a  uniform  pressure,  and  the 
machine  employed  is  fitted 
with  a  pair  of  gun-metal  rol- 
lers, cylindrical  in  shape,  by 
which  the  mill  cakes  are 
ground  to  fine  particles. 

Original 
On  this  floor  we  also  have  a 
competent  vulcanizing  depart- 
ment under  the  supervision  of 
R.  M.  Smith,   whose  father 
was  for  years  in  the  employ  of 


Sentences 


Revised 


A  process  of  "breaking 
down"  is  now  necessary  to  re- 
duce the  mill  cake  to  a  fine 
meal  so  that  it  can  receive 
a  uniform  pressure.  The 
machine  employed  to  accom- 
plish this  result  is  fitted  with 
a  pair  of  gun-metal  rollers, 
cylindrical  in  shape,  by 
which  the  mill  cakes  are 
ground  to  fine  particles. 

Revised 
On  this  floor  we  also  have 
a  completely  equipped  vul- 
canizing department  under 
the  supervision  of  Mr.  R.  M. 
Smith.     Mr.  Smith  uses  only 


THE  SENTkNOE 


lOI 


our  company,  and  who  uses 
none  but  the  best  stock  in 
the  market  in  the  production 
of  work  which  is  well  and 
widely  known. 

Original 
It  was  a  west-bound  pas- 
senger train  stalled  at  Well- 
ington by  snow-blockades 
that  was  swept  to  destruction 
at  the  beginning  of  last  March 
together  with  four  electric 
locomotives  used  in  the  Cas- 
cades tunnel,  which  had  been 
recently  electrified  under  the 
direction  of  Mr.  James  P. 
Ballentine,  the  well-known 
engineer,  and  a  part  of  the 
town  of  Wellington. 


the  best  stock  in  the  market, 
and  his  work  is  well  and 
widely  known. 


Revised 
Last  March  a  west-bound 
passenger  train,  which  had 
been  stalled  at  Wellington  by 
snow-blockades,  four  electric 
locomotives,  which  had  been 
in  use  in  the  recently  elec- 
trified Cascades  tunnel,  and 
a  part  of  the  town  of  Welling- 
ton itself  were  together  swept 
to  destruction  by  a  snow 
avalanche. 


2.  Coordination  and  Subordination 

An  analysis  of  our  mental  processes  will  often  show 
that  of  a  group  of  associated  ideas  which  crowd  our  minds 
at  the  same  time  some  are  relatively  important  and  others 
relatively  unimportant.  Good  sentence  construction 
demands  that  whenever  such  closely  associated  ideas 
are  expressed  in  the  same  sentence,  the  important  thought 
be  expressed  in  the  principal  clause  and  the  subordinate 
thoughts  in  subordinate  clauses  or  phrases.  For  example, 
if  the  two  thoughts,  "The  fireman  opened  his  dinner- 
pail,"  and  "The  boiler  exploded,"  are  to  be  united  in 
one  sentence,  it  is  better  to  write,  "Just  as  the  fireman 
opened  his  dinner-pail — (the  obviously  subordinate  idea 
expressed  in  a  subordinate  clause) — the  boiler  exploded" — 


I02     COMPOSITION  OF  TECHNICAL  PAPERS 

(the  obviously  main  idea  expressed  in  principal  clause) — 
rather  than  "The  fireman  opened  his  dinner-pail — (sub- 
ordinate idea  expressed  in  principal  clause) — ^just  as  the 
boiler  exploded" — (the  main  idea  expressed  in  a  sub- 
ordinate clause).  In  other  words,  the  structure  of 
the  sentence  should  reflect  accurately  the  relative 
importance  of  the  ideas  which  it  contains. 

A  tendency  which  should  be  especially  guarded  against 
is  that  of  stringing  ideas  together  loosely  by  simply 
adding  one  independent  clause  to  another  with  no 
attempt  to  indicate  relative  importance  of  ideas.  This 
fault  results  in  a  perfectly  flat,  monotonous,  childish 
style,  in  which  all  ideas  expressed  seem  of  equal  im- 
portance. It  is  illustrated  in  the  following  thought- 
lessly written  sentence,  in  which,  it  will  be  observed,  there 
has  been  no  attempt  whatever  at  subordination: 

**We  learned  that  it  would  take  some  time  to  repair 
the  automobile,  so  we  walked  to  the  nearest  village,  had 
some  lunch,  and  returned  to  the  scene  of  the  accident, 
but  the  machine  was  still  out  of  repair,  so  we  tried  to 
help  the  driver  fix  it,  but  our  efforts  were  all  in  vain,  so 
we  sat  down  and  waited  for  another  car  to  come  along." 

The  method  of  correcting  sentences  which  have  errors 
of  excessive  coordination  or  of  incorrect  coordination 
and  subordination  is  so  to  reconstruct  them  that  the 
structural  importance  of  the  ideas  corresponds  to  their 
logical  importance.  Often  the  sentence  can  be  best 
improved  by  an  actual  absorption  of  one  or  more  of  the 
predications  as  in  the  following  sentence: 

Original  Revised 

This  fact  rendered  the  pro-  This  fact  rendered  the  pro- 
gress of  the  work  very  slow,     gress  of  the  work  very  slow. 


THE  SENTENCE  103 

and  the  cost  of  excavation  ran  and  thereby  increased  the  cost 
up  to  an  almost  prohibitive  of  excavation  to  an  almost 
figure.  prohibitive  figure. 

The  compactness  and  singleness  in  point  of  view  make 
the  corrected  sentence  much  more  effective  and  readable 
than  the  original  one. 

Mere  structural  subordination  of  the  dependent  idea 
to  the  principal  one  is  usually  not  enough;  the  quality 
of  the  subrelationship  should  also  be  shown,  whether 
temporal,  causal,  or  what  not.  For  example,  it  is  better 
to  write,  ''Since  the  pulley  had  a  bad  flaw,  it  gave  way 
while  the  machine  was  in  full  operation,"  than  "Being 
a  pulley  with  a  bad  flaw,  it  gave  way  while  the  machine 
was  in  full  operation."  The  participial  phrase  of  the 
second  sentence  is  quite  colorless;  the  adverb-clause  of 
the  first  sentence  indicates,  on  the  other  hand,  the  rela- 
tion of  cause  and  result  existing  between  the  two  ideas. 

Careful  attention  to  subordination  and  coordination 
results  in  variety  and  richness  in  style  and  accuracy  and 
perspective  in  the  expression  of  related  ideas. 

Corrected  Sentences 
Original  Revised 

Experience  has  proved  that  Experience  has  proved  that 

the  latter  method  has  many  the  latter  method  has  many 
advantages,  the  cost  being  advantages.  Of  these  the 
here  considered  first.  first  which  will  here  be  con- 

sidered is  the  cost. 

Original  Revised 

The  engine  was  on  its  way  As  the  engine  was  on  its 

to  a  fire  when  it  skidded  in  way  to  a  fire,  it  skidded  in 

making  a  turn  and  was  top-  making  a  turn  and  toppled 

pled  over.  over. 


I04    COMPOSITION  OF  TECHNICAL  PAPERS 

Original  Revised 
The  external  characteristic  The  external  characteristic 
is  a  clean,  smooth  curve  ris-  is  a  clean,  smooth  curve, 
ing  rather  rapidly  at  first,  and  which  rises  rather  rapidly  at 
then,  as  the  field  becomes  first  and  then  gradually 
saturated,  it  gradually  droops  droops  over  as  the  field  be- 
over,  comes  saturated. 

Original  Revised 

The  outer  casing  is  to  be         The  outer  casing  is  to  be 

of  either  cast  iron  or  steel  either  of  cast  iron,  or  of  steel 

plate  with  cast-iron  base  and  plate  with  cast-iron  base;  with 

top-plate,    the    whole  being  either  construction  the  whole 

substantially     and      rigidly  is    to    be   substantially   and 

braced.  rigidly  braced. 

3.  Parallelism 

In  the  planning  of  a  sentence  one  of  the  most  useful 
rhetorical  devices  is  that  known  as  parallelism.  The 
principle  of  parallelism  demands  that  whenever  two  or 
more  ideas  perform  the  same  logical  function,  that  fact 
should  be  shown  by  a  similarity  of  structure  of  the 
different  phrases  or  clauses  which  embody  them.  The 
following  sentence  exhibits  very  bad  parallelism: 

"Such  stunts  as  (i)  forcing  a  student  from  his  room, 

(2)  compelling  him  (a)  to  roll  peanuts  with  his  nose, 

(3)  barking  at  the  moon,  and  (4)  proposing  to  coeds  at 
Harmony  Hall  are  not  likely  to  result  in  severe  bodily 
injury." 

The  parallel  phrasing  of  this  sentence  indicates  that 
(i)  forcing,  (2)  compelling,  (3)  barking,  and  (4)  proposing 
all  have  the  same  logical  function,  and  that  (a)  to  roll 
stands  quite  alone.  But  this  is  not  true;  the  sophomores 
do  the  (i)  forcing  and  the  (2)  compelling,  and  the  fresh- 


THE  SENTENCE  105 

men  do  the  (3)  harking  and  the  (4)  proposing,  and  {a) 
to  roll  is  not  logically  isolated.  Incidentally,  forcing 
and  compelling  are  not  stunts.  With  the  phrases  cor- 
rectly paralleled  so  as  to  show  the  proper  logical  associa- 
tion of  ideas,  the  sentence  will  be  written  as  follows: 

*'  (i)  Forcing  a  student  from  his  room  and  (2)  compell- 
ing him  to  perform  such  stunts  as  {a)  to  roll  peanuts 
with  his  nose,  {b)  bark  at  the  moon,  and  (c)  propose  to 
coeds  at  Harmony  Hall  are  not  likely  to  result  in  severe 
bodily  injury," 

Here  the  structural  form  shows  at  a  glance  the  proper 
relationship  between  (i)  forcing  and  (2)  compelling,  on 
the  one  hand,  and  (a)  to  roll,  (b)  (to)  bark,  and  (c)  (to) 
propose,  on  the  other  hand. 

Bad  parallelism  may  result  from  the  failure  to  place 
the  two  members  of  a  pair  of  correlative  conjunctions 

{not  only but  also;  either or-,  neither nor 

both and',  whether or;  etc.)  before  coordinate 

sentence  elements.  The  following  sentence  illustrates 
this  fault: 

*' Before  a  sentence  can  be  said  to  be  well  written,  not 
only  must  it  be  correct  in  grammar,  but  vigorous  in 
construction  also.^^ 

In  order  that  the  correlatives  here  may  precede  co- 
ordinate sentence  elements,  this  sentence  must  be 
written : 

"Before  a  sentence  can  be  said  to  be  well  written,  it 
must  be  not  only  correct  in  grammar  but  also  vigorous  in 
construction." 

Here  the  correlative  conjunctions  precede  correspond- 
ing coordinate  adjectives. 

Care  should  be  taken  not  to  indicate  a  parallelism  of 


io6    COMPOSITION  OF  TECHNICAL  PAPERS 


construction  where  the  sentence  members  concerned  are 
not  actually  coordinate.  The  following  sentence  illus- 
trates this  fault: 

''Drawing  instruments  must  be  kept  (a)  clean,  (b) 
free  from  dust,  and  {c)  must  be  well  oiled." 

Here  the  omission  of  the  conjunction  and  between  (a) 
and  (h)  indicates  that  (a),  {b),  and  (c)  are  structurally- 
coordinate;  such  is  not,  however,  the  case.  This  sen- 
tence should  be  written  either: 

"Drawing  instruments  must  be  kept  {a)  clean,  {b)  free 
from  dust,  and  {c)  well  oiled,"  or, 

"Drawing  instruments  must  be  kept  (ai)  clean  and 
(a2)  free  from  dust,  and  (b)  must  be  well  oiled." 


Corrected 
Original 
It  is  usually  the  most 
practicable  to  allow  the  tile  to 
be  laid  directly  on  the  sand, 
and  bend  all  efforts  to  keep- 
ing the  tile  clean,  superfluous 
water  drained  away,  and  the 
prevention  of  flood  water 
overflowing  the  tile. 

Original 
Overheating  of  gas-engine 
cylinders  may  be  due  to  im- 
proper flow  of  water  through 
the  cylinder  -water  jacket,  to 
the  water  jacket's  having  be- 
come coated  with  scale,  or  to 
have  an  accumulation  of  dirt 
it  in. 


Sentences 

Revised 
It  is  usually  the  most 
practicable  to  allow  the  tile  to 
be  laid  directly  on  the  sand, 
and  then  to  bend  all  efforts 
toward  keeping  the  tile 
clean,  superfluous  water 
drained  away,  and  flood 
water  from  overflowing  the 
tile. 

Revised 
Overheating  of  gas-engine 
cylinders  may  be  due  either 
to  improper  flow  of  water 
through  the  cylinder  water 
jacket,  or  to  an  accumulation 
of  scale  or  dirt  in  the  jacket. 


THE  SENTENCE 


107 


Original 
When  planning  a  tile  sys- 
tem, an  engineer  is  in  danger 
of  being  misled  by  the  ap- 
pearances of  the  low  lands  as 
compared  with  the  soggy, 
wet  lands,  and  thorough 
drainage  planned  for  the  wet 
lands  and  little  or  none  for 
the  lands  lying  higher  up  the 
slope. 

Original 
The  bearings  shall  permit 
of  ready  inspection,  adjust- 
ments, and  be  accessible  for 
repairs. 


Revised 
When  planning  a  tile  sys- 
tem, an  engineer  is  in  danger 
of  being  misled  by  the  ap- 
pearance of  the  low  lands  as 
compared  with  that  of  the 
soggy,  wet  lands,  and  of  pro- 
viding thorough  drainage  for 
the  wet  lands  and  little  or 
none  for  the  lands  lying 
higher  up  the  slope. 

Revised 
The  bearings  shall  permit 
of  ready  inspection  and  ad- 
justments, and  shall  be  access- 
ible for  repairs. 


4.  Dangling  Modifiers 

Three  types  of  dangling  modifier  will  be  considered: 
(A)  the  dangling  participial  phrase;  (B)  the  dangling 
gerund  phrase;  and  (C)  the  dangling  elliptical  clause. 

{A)  Dangling  Participial  Phrase. — A  participial  phrase 
is  said  to  be  dangling  when  the  substantive — noun  or 
pronoun — which  it  modifies  is  not  clearly  indicated. 
In  the  following  sentence  the  participial  phrase  is  not 
dangling: 

^^  Stepping  up  to  the  man  in  the  checked  suit,  the  officer 
tapped  him  on  the  shoulder." 

Here  the  phrase  stepping  up  to  the  man  in  the  checked 
suit  very  clearly  modifies  officer;  it  was  he  who  did  the 
stepping  up.  In  the  following  sentence,  however,  the 
participial  phrase  is  dangling,  that  is,  structurally  de- 


io8    COMPOSITION  OF  TECHNICAL  PAPERS 

pendent  upon  no  substantive  with  which  it  can  logically 
be  connected: 

"There  were  plenty  of  woodchucks  on  the  farm,  but 
not  being  very  tame,  I  never  got  near  one." 

Now  certainly  the  writer  does  not  mean  that  "I  was 
not  very  tame;"  and  yet  /  is  the  only  substantive  ex- 
pressed with  which  the  phrase  is  structurally  connected. 
What  the  writer  meant  to  say  is: 

"There  were  plenty  of  woodchucks  on  the  farm,  but 
not  being  very  tame,  they  kept  away  from  me,"  or, 

"There  were  plenty  of  woodchucks  on  the  farm,  but 
since  they  were  not  very  tame,  I  never  got  near  one." 

In  this  case  the  error  has  led  merely  to  an  absurdity; 
many  such  misconstructions  result,  however,  when  the 
common-sense  of  the  reader  can  not  make  the  correction, 
in  positive  ambiguity  and  misunderstanding. 

Dangling  participial  phrases  need  not  come  at  the  be- 
ginning of  the  sentence;  often  they  occur  within  the 
sentence  or  at  the  end  as  in  the  following  sentence: 

"Before  they  began  work,  they  oiled  the  engines, 
followed  by  a  tightening  of  all  the  belts. ^^ 

The  writer  should  have  written: 

"Before  they  began  work,  they  oiled  the  engines  and 
tightened  all  the  belts." 

Sentences  containing  dangling  participial  phrases 
should  be  corrected  by  expressing  the  idea  of  the  phrase 
in  a  complete  dependent  clause  or  by  reconstructing  the 
principal  clause  so  that  the  relationship  between  the 
phrase  and  the  substantive  modified  is  at  once  apparent. 

(B)  Dangling  Gerund  Phrases. — A  gerund  phrase  is  a 
phrase  introduced  by  a  verbal  noun  {running,  jumping, 
speaking,  etc.)  which  is  the  object  of  a  preposition. 
Such   a   phrase  is  said   to  be   dangling  whenever   the 


THE  SENTENCE  109 

agent  implied  by  the  gerund  is  not  immediately  clear. 
In  the  following  sentence  the  gerund  phrase  is  not 
dangling: 

*'/w  attempting  to  make  the  connection,  he  received  the 
full  force  of  the  current." 

Here  the  he,  clearly  used  as  the  subject  of  the  main 
verb,  is  obviously  the  person  who  attempted  to  make  the 
connection,  and  there  is  no  possible  misunderstanding. 
In  the  following  sentence  the  gerund  phrase  is  also  not 
dangling: 

"/w  loading  a  plate-holder,  great  care  is  necessary  to  keep 
out  the  dust." 

Here  the  writer  has  in  mind  a  general  act;  he  is  not 
thinking  of  any  definite,  active  agent — therefore,  there 
need  be  none  expressed. 

The  following  sentence  is,  on  the  other  hand,  bad: 

^^  After  pulling  in  the  gang-plank,  the  propellers  of  the 
great  ship  began  slowly  to  revolve." 

Did  the  propellers  pull  in  the  gang-plank?  Certainly 
not,  and  yet  that  is  what  the  writer  has  said.  What  he 
means  is: 

^^  After  the  gang-plank  had  been  pidled  in  (or,  ^^  After 
the  sailors  had  pulled  in  the  gang-plank),  the  propellers 
of  the  great  ship  began  slowly  to  revolve." 

Sentences  containing  dangling  gerund  phrases  should 
be  corrected  in  a  manner  similar  to  that  employed  in 
the  case  of  sentences  containing  dangling  participial 
phrases. 

(C)  Dangling  Elliptical  Clauses. — An  elliptical  clause 
is,  as  the  name  implies,  a  clause  from  which  the  subject 
and  predicate  have  been  omitted.  Unless  the  omitted 
subject  of  the  clause  is  the  same  as  the  subject  of  the 
main  verb  of  the  sentence,  the  clause  is  dangling.     In 


no     COMPOSITION  OF  TECHNICAL  PAPERS 

the  following  sentence  the  elliptical  clause  is  correctly 
employed: 

^^  While  experimenting  in  the  laboratory,  the  chemist 
discovered  a  new  element." 

Here  while  experimenting  is  seen  at  once  to  be  an  ellip- 
tical expression  for  while  the  chemist  was  experimenting; 
the  subject  which  was  omitted  is  the  same  as  that  of  the 
main  verb. 

In  the  following  sentence,  however,  the  clause  is  in- 
correctly used: 

"  When  only  twenty  years  old,  his  j other  formed  a  part- 
nership with  him." 

Was  his  father  only  twenty  years  old  at  the  time  of  this 
business  arrangement?  Structurally  father  is  the  only 
noun  in  the  principal  clause  which  can  be  identified  with 
the  omitted  subject  of  the  verb  in  the  elliptical  clause. 
What  the  writer  means  is: 

^^When  only  twenty  years  old,  he  formed  a  partnership 
with  his  father,"  or, 

**  When  he  was  only  twenty  years  old,  his  father  formed 
a  partnership  with  him." 

A  sentence  containing  a  dangling  elliptical  clause 
should  be  corrected  either  by  supplying  the  omitted 
subject  and  predicate  in  the  incomplete  clause,  or  by 
so  reconstructing  the  principal  clause  that  the  subject 
of  the  main  verb  is  the  same  as  the  omitted  subject  of 
the  elliptical  clause. 

Corrected  Sentences 
{A)  Dangling  Participial  Phrases 
Original  Revised 

Stepping  into  the  machine  Stepping  into  the  machine 

shop  a  gigantic  crane  is  seen,      shop  the  visitor  sees  a  gigan- 
tic crane. 


THE  SENTENCE 


III 


Original 
Here  the  sulphur  in  the  gas 
is  oxidized,  thus  preventing 
the  formation  of  sulphuric 
acid,  which  would  injure  the 
machine. 

Original 
In  arranging  the  apparatus 
for  the  experiment,  I  always 
set  out  on  the  table  the  flasks 
which  I  shall  need  followed 
by  all  the  chemicals  necessary . 

Original 
The  mixture  is  lightly 
sprinkled  with  water  just  be- 
fore the  blocks  are  placed; 
making  a  rich  mortar  of  the 
layer. 


Revised 
Here  the  sulphur  in  the  gas 
is  oxidized,  a  change  that  pre- 
vents the  formation  of  sul- 
phuric acid,  which  would  in- 
jure the  machine. 

Revised 
In  arranging  the  apparatus 
for  the  experiment,  I  always 
set  out  on  the  table  first  the 
flasks  which  I  shall  need,  and 
then  all  the  necessary  chem- 
icals. 

Revised 
The     mixture     is     lightly 
sprinkled  with  water  just  be- 
fore the  blocks  are  placed; 
this  dampening  makes  a  rich 
mortar  of  the  layer. 


{B)  Dangling  Gerund  Phrases 


Original 
On  making  some  tests  with 
atmospheres  of  steam,  a  rise 
of  the  mercury  higher  than 
what  might  have  been  ex- 
pected was  noted  by  the 
experimenters. 

Original 

In  considering  the  subject 

of    oxidation     temperatures, 

freshly-mined  coal  was  found 

almost  immediately  to  exude 


Revised 
On  making  some  tests  with 
atmospheres  of  steam,  the  ex- 
perimenters noted  a  rise  of 
the  mercury  higher  than  what 
might  have  been  expected. 

Revised 

In  considering  the  subject 

of    oxidation    temperatures, 

the  investigators  found  that 

freshly-mined  coal  almost  im- 


112     COMPOSITION  OF  TECHNICAL  PAPERS 


hydrocarbons  and  to  absorb      mediately   exudes   hydrocar- 
oxygen.  bons  and  absorbs  oxygen. 

(C)  Dangling  Elliptical   Clauses 


Original 
While  standing  at  the  east 
end  of  the  shop,  a  loosened 
bolt  from  a  crane  fell  and 
struck  him  on  the  shoulder. 


Revised 

While  he  was  standing  at 
the  east  end  of  the  shop,  a 
loosened  bolt  from  a  crane 
fell  and  struck  him  on  the 
shoulder, 

or. 

While  standing  at  the  east 
end  of  the  shop,  he  was  struck 
on  the  shoulder  by  a  falling 
bolt  from  a  crane. 

Revised 
While  he  was  wearing  socks 
and  boots  that  he  had  had  on 
all  day  and  that  were,  there- 
fore, fairly  moist  with  perspi- 
ration, a  comparatively  large 
current  passed  through  his 
body. 


Original 
When  wearing  socks  that 
had  been  in  use  the  whole 
day,  and  were  therefore  fairly 
impregnated  with  perspira- 
tion, and  wearing  the  boots 
he  had  also  worn  the  whole 
day,  and  were  therefore  also 
fairly  moist,  a  comparatively 
large  current  passed  through 
his  body. 

5.  Weak  Reference 

Pronouns  are,  literally,  words  used  instead  of  nouns. 
A  pronoun  has  no  meaning  in  itself  but  is  understandable 
only  when  the  substantive  which  it  represents,  its 
antecedent,  is  known.  Thus,  "He  is  here"  does  not 
convey  a  full  meaning  until  we  know  what  noun  he 
stands  for.  It  is,  then,  obvious  that  the  use  in  a  sentence 
of  a  pronoun  the  antecedent  of  which  is  not  at  once 


THE  SENTENCE  113 

evident  leads  to  an  ambiguous,  vague,  and  sometimes 
entirely  incorrect  understanding  of  the  idea.  With  the 
so-called  indefinite  pronouns  no  definite  antecedent  is 
necessary;  one  may  say  "One  must  always  keep  his 
fountain  pen  well  filled,"  because  one  here  does  not  need 
to  represent  a  definite  substantive.  When  other  pro- 
nouns are  used,  however,  the  substantive  to  which  they 
refer  must  be  unmistakably  clear.  When  it  is  not,  the 
reference  of  the  pronoun  is  said  to  be  weak. 

To  correct  weak  reference  in  a  sentence  it  is  necessary, 
of  course,  either  to  employ  a  noun  in  place  of  the  mean- 
ingless pronoun,  or  so  to  reconstruct  the  sentence  as  to 
make  the  antecedent  of  the  pronoun  unmistakable.  It 
is  well  usually  to  have  the  pronoun  as  near  to  the  ante- 
cedent as  possible;  especial  care  is  required  to  prevent 
the  intrusion  between  pronoun  and  antecedent  of  another 
noun  to  which  the  pronoun  might  seem  to  refer.  Occa- 
sionally the  most  satisfactory  correction  can  be  secured 
from  an  entire  replanning  of  the  sentence. 

Corrected  Sentences 
Original  Revised 

The  inexperienced  foreman  The  work  of  digging  the 

had  the  work  of  digging  the  guy  hole  was  assigned  to  the 
guy  hole  which  resulted  in  foreman  who  was  inexperi- 
being  too  near  the  post  for  the  enced;  as  a  result  the  hole 
strain  guy.  was  too  near  the  post  for  the 

strain  guy. 

Original  Revised 
A    fireman    should    never         A    fireman    should    never 
sleep  while  on  duty;  that  is  sleep  while  on  duty;  such  care- 
highly  dangerous.  lessness  is  highly  dangerous. 


114    COMPOSITION  OF  TECHNICAL  PAPERS 

Original  Revised 

A  bolt  and  nut  may  be  held  The  following  method  sel- 

in  the  end  of  a  turning  crank  dom  fails  to  hold  a  bolt  and 

or  shafting  by  the  following  nut  in  the  end  of  a  turning 

method,  which  seldom  fails,  crank  or  shafting  even  when 

even  though  it  is  inclined  to  the   nut  "has  a  tendency  to 

work  loose.  work  loose. 

Original  Revised 
A  common  trouble  be-  A  common  trouble  be- 
tween engineers  and  their  tween  engineers  and  their 
clients  is  that  they  do  not  clients  is  that  the  engineers 
have  the  proper  respect  for  do  not  have  proper  respect 
them.  for  the  clients. 


6.  Order  of  Parts 

In  the  section  of  this  chapter  which  deals  with  the 
grammatical  structure  of  the  sentence  it  is  shown  that 
many  sentences — all,  in  fact,  but  the  very  shortest  and 
simplest — contain  modifying  phrases  and  clauses.  Now 
it  is  obvious  that  whenever  in  a  sentence  it  is  difficult 
to  understand  at  once  just  what  noun  or  verb  a  given 
adjective  or  adverb  or  adjective-  or  adverb-phrase  or 
clause  modifies,  the  result  is  likely  to  be  a  confused  and 
blurred  conception  of  the  idea.  Such  confusion  often 
arises  from  a  loose  arrangement  of  the  elements  of  the 
sentence,  from  a  lack  of  care  in  putting  modifiers  next 
to  the  words  which  they  modify.  This  lack  of  care  is 
evident  in  the  following  sentence: 

*'The  smooth  vacuum  cups  wash  anything  from  the 
most  delicate  and  sheerest  laces  to  rag-rugs,  heavy 
bedding,  or  blankets  without  tearing.'* 

Here  the  phrase  without  tearing  would  seem  from  its 


THE  SENTENCE  115 

position  to  be  an  adjective-phrase  modifying  the  noun 
blankets;  it  is,  of  course,  an  adverb-phrase  modifying  the 
verb  wash.     The  sentence  should  read: 

*'The  smooth  vacuum  cups  wash  without  tearing, 
anything  from  the  most  deHcate  and  sheerest  laces  to 
rag-rugs,  heavy  bedding,  or  blankets." 

The  comma  has  been  used  after  tearing  to  prevent 
mistaken  junction  of  tearing  and  anything. 

The  following  sentence  is  also  ineffective  because  of  a 
bad  arrangement  of  parts: 

"A  perfect  bond  must  at  all  points  be  secured  with 
the   underlying  concrete." 

This  should  read: 

*'A  perfect  bond  with  the  underlying  concrete  must 
be  secured  at  all  points." 

A  very  frequent  displacement  in  sentence  construction 
is  that  of  single  adverbs,  especially  of  the  adverb  only. 
An  adverb  should  be  so  placed  that  the  verb,  adjective, 
or  other  adverb  which  it  modifies  is  unmistakably  evident. 
One  should  not  write,  "I  only  earn  fifteen  dollars  a 
week,"  as  though  the  writer  means  to  emphasize  the 
fact  that  he  does  not  spend  or  save  that  amount,  when  he 
really  means,  "I  earn  only  fifteen  dollars  a  week."  The 
adverb  should  be  so  placed  that  it  is  seen  to  modify  not 
the  verb  earn,  but  the  adjective  _^//eew. 

Corrected  Sentences 
Original  Revised 

Another    perforated    ring  Another    perforated    ring, 

showers  water  over  the  head  which  is  made  of  metal, 
which  is  made  of  metal.  showers  water  over  the  head. 


ii6    COMPOSITION  OF  TECHNICAL  PAPERS 


Original 
A  water  seam  was  struck 
about   four   feet   below    the 
rock   surface   which   proved 
troublesome. 

Original 
It  is  the  writer's  observa- 
tion that  dry  rot,  being  a 
fungus  growth,  will  only- 
attack  structural  timbers 
when  a  certain  degree  of 
humidity  is  present. 

Original 
This  form  of  combustion 
chamber  is  not  possible  in 
the  construction  of  the 
poppet  valve  motors  because 
of  the  presence  of  pockets  in 
the  cylinder  walls  which  have 
a  small  volume  and  a  very 
large  heating  surface. 


Revised 
A  water  seam  which  proved 
troublesome  was  struck  about 
four    feet    below    the    rock 
surface. 

Revised 
It  is  the  writer's  observa- 
tion that  dry  rot,  being  a 
fungus  growth,  will  attack 
structural  timbers  only  when 
a  certain  degree  of  humidity 
is  present. 

Revised 
This  form  of  combustion 
chamber  is  not  possible  in 
the  construction  of  the 
poppet  valve  motors  because 
of  the  presence  in  the  cyl- 
inder walls  of  pockets  which 
have  a  small  volume  and  a 
very  large  heating  surface. 


7.  Logical  Agreement 

Many  sentences  are  bad  because  of  illogical  agreement 
between  parts.  In  general,  this  fault  usually  results 
from  the  writer's  failing  to  say  just  what  he  meant  to 
say.  Sometimes  the  lack  of  logic  is  apparent  in  the  cir- 
cumstance that  an  expressed  or  implied  comparison  is 
made  up  of  elements  which  can  not  be  compared.  Occa- 
sionally, too,  the  writer  is  guilty  of  saying  that  something 
is  something  else  which  it  can  not  possibly  be.  An  excel- 
lent example  of  an  illogical  statement  follows: 


THE  SENTENCE  117 

"There  is  quite  a  gap  between  these  boys,  usually  office 
boys  and  messengers,  and  the  positions  as  shippers,  etc., 
and  to  get  them  there  I  propose  the  apprentice  system." 

Now  how  can  a  gap  exist  between  boys  and  positions? 
There  can  be  a  gap  between  messenger  boys  and  shippers, 
or  between  the  positions  which  the  boys  hold  and  those 
which  the  shippers  hold,  but  the  writer  has  not  said  so. 
The  sentence  might  be  rewritten  so  as  to  read: 

"There  is  quite  a  gap  between  the  places  held  by  these  boys, 
usually  office  boys  and  messengers,  and  the  positions  held 
by  shippers  and  employees  of  similar  rank;  and  to  get  the 
boys  over  the  gap  I  propose  the  apprentice  system.'* 

To  correct  illogical  statements  it  is  necessary  first  to 
perceive  clearly  at  what  point  in  the  sentence  the  bad 
logic  exists;  and  then  so  to  reconstruct  the  entire  sentence 
that  it  is  the  exact  and  logical  expression  of  the  idea 
which  the  writer  wishes  to  convey. 

Corrected  Sentences 
Original  Revised 

This  cost  is  less  than  many  This    cost    is    less    than 

miles  of  macadam  road.  that  of  many  miles  of  maca- 

dam road. 

Original  Revised 

A  test  quite  as  important  A  test  quite  as  important 

as  the  one  just  mentioned  is      as   the   one  just   mentioned 
the  flashing  point.  is    that    to    determine    the 

flashing  point. 

Original  Revised 

The  test  for  ash  consists  The  test  for  ash  consists 

of  burning  a  portion  of  the  of  burning  a  portion  of  the 

sample    and     weighing     the  sample,  weighing  the  residue, 


ii8    COMPOSITION  OF  TECHNICAL  PAPERS 

residue,  and  the  per  cent,  is  and  determining  in  a  manner 
found  in  a  similar  manner  to  similar  to  that  employed  in 
the  other  tests.  the    other    tests    what    per- 

centage   of    the    whole    this 
residue  forms. 

8.  Incomplete  Statement 

Bad  sentences  often  result  from  the  attempt  of  the 
writer  to  express  his  ideas  more  concisely  by  omitting 
necessary  words  and  phrases.  This  practice  of  making 
the  reader  supply  the  omitted  words  often  results 
absurdly,  as  in  the  following  notice  impaled  recently  on 
a  hook  in  the  coat-room  of  a  college  recitation  hall: 

*'  Will  the  student  who  removed  my  coat  from  this  hook 
by  mistake  last  Friday  morning  kindly  return  and  hang 
on  the  hook?" 

Now  however  perturbed  in  spirit  the  writer  of  this 
notice  may  have  been,  he  certainly  did  not  desire  capital 
punishment  for  the  student  who  had  carelessly  carried 
off  his  coat.     What  he  quite  obviously  meant  to  write  is: 

"Will  the  student  who  removed  my  coat  from  this 
hook  by  mistake  last  Friday  morning  please  return  the 
coat  to  the  hook?" 

Incorrect  omissions  of  auxiliary  verbs  in  compound 
sentences  are  very  frequent.  The  following  sentence 
illustrates  such  an  omission: 

"The  door  is  then  bolted  and  the  windows  securely 
locked." 

Here  the  auxiliary  verb  is  of  the  first  clause  is  incor- 
rectly allowed  also  to  serve  with  a  noun  in  the  plural 
number  in  the  second  clause.     The  sentence  should  read : 

"The  door  is  then  bolted,  and  the  windows  are  se- 
curely locked." 


THE  SENTENCE 


119 


Corrected  Sentences 
Original 
I    have    tried    dipping    in 
sulphuric  acid  but  still  have 
some  spots. 


Original 
While    storage    bins    are 
built  of  concrete  and  steel, 
the  prevailing  practice  is  to 
build  them  of  timber. 


Revised 
Although  I  have  tried  to 
clean  (the  rusty  instruments) 
by  dipping  them  in  sulphuric 
acid,  I  have  not  been  able 
even  by  this  method  to  re- 
move all  the  spots. 

Revised 
Although  storage  bins  are 
occasionally  built  of  concrete 
and  steel,  the  prevailing 
practice  is  to  build  them  of 
timber. 


Original 
The  working  man  careful 
in  these  operations  without 
the  use  of  a  file  the  teeth 
will  work  fairly  well. 


Revised 
If    the    working    man    is 
careful   in   these  operations, 
the  teeth  will  cut  fairly  well 
even  if  they  are  not  filed. 


Original 
It  is,  as  it  were,  but  a  fort- 
night since  the  idea  of  an 
aeronaut  flying  head  down, 
looping  the  loop,  and  even 
defying  the  skill  of  the  birds, 
who  have  been  supreme  in 
the  air  all  the  past  centuries. 


Revised 
It  is,  as  it  were,  but  a 
fortnight  since  the  idea  origi- 
nated of  an  aeronaut  flying 
head  down,  looping  the  loop, 
and  even  defying  the  skill  of 
the  birds,  who  have  been 
supreme  in  the  air  all  the  past 
centuries. 

(At  best  this  is  a  flabby  sen- 
tence; the  thought  is  con- 
ventional, and  the  phrases 
are  inflated.) 


I20    COMPOSITION  OF  TECHNICAL  PAPERS 

Original  «  Revised 

This  boiler  is  in  need  of  This  boiler  is  in  need  of 
repair,  for  the  lining  is  badly  repair,  for  the  lining  is  badly 
scaled  and  the  bolts  loose.  scaled,    and    the    bolts    are 

loose. 


9.  Weak  Emphasis 

It  is  not  enough  that  a  sentence  be  clear;  the  ideas 
which  it  contains  must  be  properly  emphasized — that  is, 
the  unimportant  ideas  must  be  made  relatively  incon- 
spicuous, and  the  important  ideas  must  be  stressed.  A 
part  of  this  light  and  shadow  in  a  sentence  will  result 
from  a  careful  attention  to  proper  coordination  and 
subordination  of  the  associated  ideas  (see  page  loi); 
but  in  addition  it  is  desirable  so  to  arrange  the  parts  of 
the  sentence  that  the  important  ideas  come  in  the  im- 
portant positions.  These  are  the  beginning,  since  words 
at  the  beginning  strike  the  attention  of  the  reader 
first  after  the  break  of  the  full  period  stop,  and  the  end, 
since  words  at  the  end  are  ordinarily  at  the  climax  of  the 
sentence  and  stand  out  also  because  of  their  position  just 
before  the  full  period  stop.  In  a  lower  degree  the  posi- 
tions just  after  and  just  before  the  semicolon  are  also 
emphatic. 

In  general,  then,  the  principle  of  good  sentence  em- 
phasis demands  that  the  fiat,  obvious,  "filler"  words  of 
the  sentence  be  tucked  away  inconspicuously  within  the 
sentence,  but  that  the  words  which  express  the  real 
thought  and  force  of  the  sentence  idea  be  emphasized  by 
a  conspicuous  position  either  at  the  beginning  or  at  the 
end.     This  has  not  been  done  in  the  following  sentence: 

"The  columns  supporting  the  outboard  end  of  the 


THE  SENTENCE  121 

generator  are  entirely  independent  of  the  rest  of  the 
foundation,  because  of  its  being  impossible  to  carry  the 
foundation  over  the  discharge- tunnel  structure." 

Here  the  leading  idea  is  contained  in  the  words 
entirely  independent  of  the  rest  of  the  foundation.  This 
idea  has,  however,  been  smothered  up  within  the  sen- 
tence, whereas  a  subordinate  idea  has  been  allowed  to 
usurp  the  emphatic  position  at  the  end.  The  sentence 
should  be  written: 

"  Since  it  was  found  impossible  to  carry  the  foundation 
over  the  discharge-tunnel  structure,  it  was  necessary  to 
make  the  columns  supporting  the  outboard  end  of  the 
generator  entirely  independent  of  the  rest  of  the  structure.''^ 

In  the  following  two  sentences,  in  which  the  necessity 
for  good  emphasis  is,  because  of  the  contrast  involved, 
very  great,  the  emphasis  is,  nevertheless,  exceedingly 
weak.  In  the  column  at  the  right  an  attempt  has  been 
made  to  improve  the  sentences. 

Original  Revised 
In  the  steam  plants,  never  In  steam  plants  the  amount 
more  than  fifteen  per  cent,  of  of  energy  in  the  coal  which  is 
the  coal  is  transformed  into  transformed  into  mechanical 
mechanical  work.  On  the  work  is  never  more  than  fif- 
other  hand,  in  the  producer-  teen  per  cent.  In  producer- 
gas  plants,  never  less  than  gas  plants,  on  the  other  hand, 
fifteen  per  cent,  of  the  energy  the  amount  of  energy  in  the 
of  the  coal  is  transformed  into  coal  which  is  transformed  into 
work.  mechanical  work  is  never  less 

than  fifteen  per  cent. 

Sentences  in  which  the  emphasis  is  weak  can  be  im- 
proved by  such  a  rearrangement  of  parts  as  will  bring 
out  the  important  ideas  and  throw  into  the  background 


122     COMPOSITION  OF  TECHNICAL  PAPERS 

the  unimportant  and  obvious  ideas.  Usually  this  will 
mean  also  a  more  logical  arrangement  of  parts;  for 
example,  the  cause  should  usually  precede  the  result  or 
effect,  and  a  detail  occurring  at  one  time  should  usually 
precede  a  detail  occurring  at  a  later  time.  The  matter 
of  proper  sentence  perspective  may  seem  in  the  case  of 
any  given  sentence  to  be  relatively  unimportant;  care 
in  such  details  produces,  however,  writing  which  is  clear 
and  vigorous;  inattention  to  these  matters  leads  to 
writing  which  is  merely  passable. 


Corrected  Sentences 


Original  ' 
The  culvert  saved  the  ap- 
paratus from  going   over   a 
retaining  wall  and  taking  an 
eight-foot  drop,  however. 

Original 
There  will  be  a  lecture  on 
The  Cause  of  Storms  on  Thurs- 
day, April  26,  at  8  p.m.  in 
the  Chemistry  Auditorium  by 
Mr.  John  J.  Patron  of  the  U.  S. 
Weather  Bureau. 

Original 
The  pat  thus  made  seemed 
to  harden,  but  disintegration 
immediately  took  place  when 
it  was  immersed  in  water. 

Original 
On  the  first  floor  of  the 
building    the   offices    of   the 


Revised 
The  culvert,  however,  saved 
the    apparatus    from    going 
over  a  retaining  wall  and  tak- 
ing an  eight-foot  drop. 

Revised 
The  Cause  of  Storms  will  be 
the  subject  of  a  lecture  by 
Mr.  John  J.  Patron  of  the 
U.  S.  Weather  Bureau  in  the 
Chemistry  Auditorium  on 
Thursday,  April  26,  at  8  p.m. 

Revised 
The  pat  thus  made  seemed 
to  harden,  but,  when  it  was 
immersed   in    water,    it    im- 
mediately disintegrated. 

Revised 
On  the  first   floor  of  the 
building  are  the  offices  of  the 


THE  SENTENCE  123 

directors  and  the  correspon-  directors,   and,   to  the  rear, 

dence  filing  rooms  are  to  be  the      correspondence      filing 

seen.     In  the  basement  the  rooms.     In    the     basement, 

storing,   packing,    and    ship-  which   is    connected    to    the 

ping  rooms,  connected  to  the  driveway  by  an  incline,  are 

driveway  by  an  incline,  are  the    storing,    packing,     and 

to  be  found.  shipping  rooms. 

Original  Revised 

Automatic  inlet  valves  give  Automatic  inlet  valves,  al- 

good  results  in  small  engines,  though  never  as  efficient  as 

while  never  as  efficient  as  the  the    mechanically    operated 

mechanically  operated  types.  types,  nevertheless  give  very 

good  results  in  small  engines. 


Defective  and  Weak  Sentences  for  Revision 

The  following  unclassified  sentences  were  taken  from 
technical  magazines  and  student  themes.  In  correcting 
each  sentence,  determine  first  by  a  careful  analysis 
wherein  the  error  or  weakness  in  construction  lies;  then 
rewrite  the  sentence,  making  a  complete  and  smooth 
revision.  Where  it  is  impossible  to  understand  the 
original  idea,  so  reconstruct  the  sentence  as  to  express 
clearly  the  thought  which  it  seems  probable  the  writer 
meant  to  convey.  It  is  often  unfair  to  a  sentence  to 
criticize  it  out  of  its  context.  An  effort  has  been  made, 
however,  to  include  in  this  exercise  no  sentences  which 
can  not  be  individually  improved  without  reference  to  the 
context.  Many  are  merely  weak,  flabby,  unemphatic, 
crude,  or  otherwise  ineffective;  such  sentences  should 
in  the  process  of  revision  be  made  more  vigorous  and 
clean-cutj'  The  aim  of  the  exercise  is  to  cultivate  in  the 
student  a  feeling  for  good  sentence  construction  and  a 


3' 


124    COMPOSITION  OF  TECHNICAL  PAPERS 

standard  of  judgment  and  taste  which  will  result  in 
increase  in  his  power  to  construct  good  sentences 
easily. 

1.  The  viscosity  is  determined  by  comparing  the  time 
required  for  a  given  amount  of  oil  to  flow  through  a 
certain  orifice  at  a  given  temperature  to  the  time  re- 
quired for  the  same  amount  of  water  under  the  same 
conditions. 

2.  Before  purchasing  this  pump,  many  different  de- 
vices for  raising  water  were  considered. 

--3.  Another  precaution  necessary  is  to  see  that  the  con- 
crete forms  a  solid  and  compact  mass,  especially  around 
the  steel,  this  being  brought  about  by  the  tamping  and 
puddling  of  the  mixture  as  it  is  being  poured. 

-  4.  First  of  all  it  might  be  well  to  state  that  all  weigh- 
ings are  made  to  four  decimal  places,  as  the  results  should 
be  accurate  to  the  tenth  of  a  per  cent. 

5.  The  cylindrical  valves  are  entirely  operated  by 
water  pressure. 

6.  On  entering  the  soldering  machine,  laborers  placed 
covers  on  the  cans. 

7.  As  soon  as  the  operator  perceives  this,  he  closes  the 
globe  valve  F,  then  the  valve  D  is  closed,  and  the  valve 
C  is  partially  opened. 

8.  I  will  not  have  men  who  have  not  had  a  college 
training  at  the  head  of  any  department. 

9.  Combustion  engines,  or  gas  engines  as  they  are  gen- 
erally known,  are  to-day  built  in  various  sizes  and  kinds. 
The  size  of  the  engine  depending  on  the  size  and  number 
of  the  cylinders. 

^,yi<:i.  At  each  suction  stroke  of  the  engine  gasoline  will 
be  drawn  into  the  vaporizing  chamber  due  to  the  slight 


c 


THE  SENTENCE  125 

vacuum  created  there,  and  it  will  be  absorbed  by  the  air 
which  is  being  drawn  in  through  another  opening. 

II.  In  many  other  industries,  such  as  the  whiskey  and 
alcohol,  distillation  plays  an  important  role  in  the  manu- 
facture of  their  products. 

. — t7.  Thousands  of  miles  of  electric  railways  have  been 
built,  many  of  them  performing  service  comparable  to 
steam  railways  both  with  motor  cars  and  locomotives, 
but  up  to  date  only  a  few  thousand  miles  of  steam  rail- 
way trackage  has  been  equipped  for  electrical  operation. 

13.  Its  widespread  use  not  only  for  automobiles, 
water  and  air-craft  as  well  as  for  stationary  uses  illus- 
trates its  wide  application. 

14.  Lost:  an  analysis  on  the  cinder  path. 

^^15.  Three  men  were  trying  to  pull  an  ice-boat  out  of 
the  water  that  had  broken  through  the  ice. 

16.  There  are  at  the  present  time  two  large  engines 
as  can  be  seen  on  the  sketch. 

17.  The  conditions  under  which  the  determination  is 
made  are  arbitrarily  fixed  so  that  the  results  obtained  by 
different  chemists  may  be  comparable  and  form  a  basis 
for  the  comparison  of  the  coals  analyzed. 

18.  When  heating  the  wet  powder  over  a  mine  lamp,  it 
exploded  violently. 

19.  My  father  was  of  Scotch  descent  while  my  mother 
was  of  German  descent. 

20.  The  main  building  of  this  plant  is  of  red  brick, 
being  about  120  feet  square,  60  feet  high,  with  only  a 
few  windows  in  the  whole  building. 

21.  Such  men  usually  have  no  knowledge  of  the  gas 
business  or  any  other  public  service  business  and  in  most 
cases  never  acquire  any  substantial  knowledge  of  the 
same  and  are  induced  to  form  the  company  and  engage 


126    COMPOSITION  OF  TECHNICAL  PAPERS 

in  the  business  by  some  construction  contractor,  who 
himself  sometimes,  is  deficient  in  knowledge,  has  never 
successfully  operated  a  plant,  and  if  so  inclined  he  could 
not  intelligently  elucidate  the  real  needs  and  require- 
ments of  a  new  gas  plant  and  the  organization  necessary 
to  bring  success. 

62.  The  Wisconsin  statutes  covering  food  products 
are  known  to  be  the  most  stringent  of  the  States. 

23.  The  way  to  avoid  all  these  errors  is  to  be  neat  and 
orderly  in  all  computations  even  though  at  first  thought 
it  seems  to  require  more  time  whereas  in  reality  the 
converse  is  true. 

^4.  Fig.  4  illustrates  a  receiver  the  bottom  of  which  is 
set  lower  than  the  pump  cylinders,  but  the  water  level 
is  above  them  because  the  receiver  is  large  in  proportion 
to  the  pump. 

^5.  No  failure  of  the  main  motor  fields  have  occurred; 
the  armature  windings  have  merely  required  repairs 
from  time  to  time. 

i6.  The  accompanying  sketch  shows  how  a  small 
machine  is  built  from  a  shaft  hanger  and  a  few  easily 
made  forgings,  which  does  not  require  much  time  to 
construct  and  is  efficient  when  put  in  operation. 

^7.  Nor  will  students  be  required  to  study  any  for- 
eign language  during  their  college  career  by  the  new 
bill. 

^8.  Direct  current  has  an  advantage  over  alternat- 
ing current  in  the  charging  of  storage  batteries,  but  due 
to  the  fact  that  storage  batteries  usually  form  only  a 
small  part  of  the  load  of  a  generating  station,  and  when 
it  is  considered  that  mercury  rectifiers  are  a  very  con- 
venient means  of  converting  a.c.  into  d.c,  it  will  be 
understood  that  this  advantage  is  a  very  slight  one. 


TEE  SENTENCE  127 

ig.  The  heating  plants  are  usually  run  by  corporations 
having  other  large  industries  under  their  control  which 
use  large  quantities  of  steam,  such  as  electric  power 
plants. 

;^.  The  small  investment  will  be  nothing  when  pro- 
rated over  five  years,  compared  with  the  benefit  of  having 
all  water  and  gas  cuts  promptly  repaired. 

31.  Instead  of  pitch  grouting,  it  is  common  practice 
in  Paris  to  flush  the  surface  with  cement  grout. 

'32.  There  are  two  divisions  in  the  open-hearth  process. 
One  basic  and  the  other  acid. 

•^3.  At  the  end  of  five  or  six  hours  the  silicon  and 
manganese  have  been  burned  out  and  the  carbon  much 
reduced. 

^.  The  method  of  operation  is  for  the  piston  to  suck 
in  the  charge  of  air  through  the  main  valve,  and  this, 
during  compression,  is  forced  right  back  into  the  vapor- 
izer, mingling  with  the  gas  generated  by  contact  of  the 
injected  oil  with  the  hot  walls  of  the  vaporizer,  which 
being  at  a  sufficiently  high  temperature,  as  soon  as  an 
explosive  mixture  is  formed,  ignites  the  charge. 

^5.  It  is  a  question  that  I  have  threshed  out  with 
myself  and  always  arriving  at  the  same  conclusion. 

16.  It  has  been  previously  stated  that  one  of  the 
advantages  of  the  modern  interurban  system  in  competi- 
tion with,  steam  roads  is  its  ability  to  transport  the 
passenger  to  more  nearly  the  exact  point  in  a  terminal 
city  to  which  he  wishes  to  go  and  often  gives  him  transfer 
privileges  upon  the  local  railway  system  if  necessary. 

37.  Before  starting  to  tamp  the  mixture  more  water 
was  mixed  in,  using  as  much  as  the  soil  would  hold. 

'  38.  In  the  Bessemer  process  the  charge  is  molten  pig 
iron,  which  contains  some  five  per  cent,  of  carbon  and 


128    COMPOSITION  OF  TECHNICAL  PAPERS 

considerable  manganese  and  silicon,  but  phosphorus  and 
sulphur  must  be  as  low  as  possible,  for  none  is  removed 
here. 

59.  The  University  Heating  Plant  is  located  on  Uni- 
versity Avenue  on  the  opposite  side  of  the  street  and  one 
square  west  of  the  Chemistry  Building.  The  building 
of  the  Heating  Plant,  which  is  rectangular  in  shape,  is 
built  of  light  pressed  brick.  A  large  black  smoke-stack 
towers  about  seventy-five  feet  above  it,  the  smoke  from 
which  is  gradually  darkening  the  red  tile  roof  of  the  plant. 

jio.  Nearly  all  the  tungsten  is  produced  from  fields  in 
Colorado  and  California,  and  in  the  former  state  the 
Boulder  field,  which  is  the  greatest  producer,  is  situated. 

*?4i.  Her  lines  are  free  and  easy  running  in  an  unbroken 
sweep  from  stem  to  stern  showing  great  strength  and 
sea-going  qualities. 

^^2.  This  company  lays  most  of  its  own  blocks,  and  a 
large  proportion  of  its  contracts  are  in  London;  these 
blocks  are  delivered  to  the  street  in  wagons. 

43.  I  gave  the  monkey  in  charge  to  one  of  the  slaves 
to  feed  and  nurse  it,  being  a  very  tender  sort  of  animal. 

44.  For  this  purpose  large  enclosed  tanks  are  used  and 
they  are  heated  by  steam  coils  arranged  along  the  inside 
of  the  tank. 

45.  With  the  new  system  the  necessity  of  carrying  a 
lantern  to  the  barn  and  the  worry  of  setting  it  in  some 
place  to  give  the  best  light  and  where  it  will  still  be 
secure  from  falUng,  is  all  eliminated. 

Jj|.6.  Four  pulleys  guide  a  small  endless  belt  around  the 
disc  and  touching  the  rollers  thereon  at  two  different 
points  diametrically  opposite  and  on  the  same  axis  of 
the  frame. 

^7.  The  salesman's  convincing,  yet  not  overbearing 


>' 


THE  SENTENCE  129 

manner,  together  with  an  accumulated  knowledge  of  the 
various  types  of  human  nature,  will  enable  him  to  con- 
vince the  customer  indirectly  the  type  of  shoe  he  is 
interested  in. 

48.  The  cost  of  gas  for  each  filling  of  a  large  balloon 
is  alone  enough  to  place  it  out  of  the  question  for  per- 
forming commercial  travel  at  reasonable  cost. 

49.  Tests  made  recently  in  England  with  the  Gambrel 
vacuum  brake  have  shown  it  to  be  highly  effective  on 
light  automobiles,  the  only  essential  to  their  use  being 
the  running  of  the  engine. 

^o.  The  cut  is  fifty  feet  deep,  three  city  blocks  in 
length,  and  is  made  in  rock  and  earth. 

^51.  The  front  spring  of  an  automobile  broke  while  on 
a  trip  and  it  was  repaired  in  the  manner  shown  in  the 
sketch. 

32.  This  point  can  be  overcome  almost  entirely  by 
drawing  the  temper  with  a  torch,  a  pair  of  hot  tongs,  or 
by  dipping  the  shank  into  hot  lead  and  letting  the  blue  just 
begin  to  run  into  the  thread. 

^3.  This  is  desired,  for,  upon  closing  the  switch,  the 
passage  of  the  electric  current  through  the  solution  causes 
silver  to  plate  out  upon  the  metal. 

)J4.  These  processes  of  course,  vary  both  in  variety  and 
in  number  according  to  the  article  and  the  use  it  is 
intended. 

'55.  A  glass  tank  contains  the  electrolyte  and  has  two 
bus-bars  fixed  to  its  top. 

^6.  The  above  theorem  only  relates  to  the  velocity  of 
the  particles. 

57.  We  frequently  receive  letters  from  users  who  have 
driven  this  car  up  hills  that  no  other  automobile  of  any 
kind  has  ever  been  able  to  negotiate;  through  mud  that 


I30     COMPOSITION  OF  TECHNICAL  PAPERS 

has  stalled  horses  and  wagons;  have  pulled  cars  of  35  and 
40  horsepower  and  their  passengers  up  grades  that  stalled 
these  cars;  driven  through  snowdrifts,  up  steep  incHnes 
covered  with  ice;  and  in  places  where  a  horse  and  buggy 
could  not  possibly  go. 

^J8.  It  is  seen  that  the  heating  of  the  water  will  be 
accelerated  due  to  the  large  heating  surface  of  the  tubes 
within  the  boiler. 

^^9.  By  wireless  from  Arlington  is  the  best  way  to  get 
the  correct  time,  because  it  is  a  government  station  and 
also  wireless  waves  travel  about  three  thousand  miles  a 
second  while  in  line  telegraphy  there  is  a  large  amount 
of  resistance  and  thus  the  time  is  not  as  accurate. 
^360.  This  system  is  probably  better  known  and  higher 
rated  than  any  known  system. 

61.  The  results,  which  were  satisfactory,  showed  that 
sawdust  is  an  excell^n^  extinguishing  agent  for  certain 
volatile  liquids,  especially  those  of  a  viscous  nature,  and 
were  presented  in  a  paper  read  at  the  recent  annual 
meeting  of  the  American  Society  of  Mechanical  Engineers 
by  Edgar  R.  Roberts,  Chicago,  who  is  identified  with  the 
inspection  department. 

62.  In  one  case  there  is  a  report  on  a  No.  300  crucible 
which  ran  forty  heats  on  manganese  bronze,  and  there  are 
dozens  of  cases  as  high  as  thirty-eight  and  forty  heats  on 
No.  loo's,  melting  car-box  metal. 

63.  The  effect  of  carelessness  was  well  illustrated  on  a 
sheet  asphalt  pavement  in  a  Western  city. 

64.  The  striking  of  a  medal  is  entirely  mechanical  and 
is  obtained  by  either  hydrauHc  pressure,  or  a  screw 
press. 

65.  Pieces  of  wood  were  planed  out  and  held  in  the 


THE  SENTENCE  131 

chuck  of  the  lathe  and  the  tool  run  on  the  wood  while  it 
was  turning. 

66.  One  trip  in  particular,  between  Toledo  and  Detroit, 
which  trip  was  made  during  a  continuous  rain  storm,  in  a 
prominent  make  of  car  belonging  to  the  writer 

67.  The  power  is  controlled  by  a  switch  on  the  handle 
by  the  operator. 

68.  These  contacts,  usually  about  eight  in  number,  are 
made  of  brass  buttons  one-half  inch  in  diameter  and 
one-eighth  inch  thick  having  a  stud  going  through  the 
slate,  and  being  connected  to  the  resistance  element  on 
the  rear. 

69.  The  lever  is  of  cast  iron  having  mounted  on  its 
under  side  a  copper  riding  contact  riding  over  the  con- 
tacts as  the  lever  is  moved  to  the  right  in  starting  the 
motor. 

70.  Many  combinations  in  electric  plants  using  boiler 
compounds  having  soda  ash  as  a  base  have  noticed  a 
tendency  to  discolor  the  distilled  water  condensate  to  a 
reddish  hue,  resulting  in  making  *'red"  ice. 

71.  Theoretically,  therefore,  but  probably  with  longer 
bearings  than  are  now  used,  this  should  produce  the  best 
results,  for  automobile  work,  if  properly  apphed. 

72.  In  seeking  an  explanation  of  the  rapid  burning  of 
fuse  in  a  number  of  experiments,  several  samples  of  the 
fuse  were  especially  treated  by  the  experimenters  so  as 
to  remove  all  the  tar  and  asphalt  in  them. 

73.  The  result  was  that  it  was  impossible  to  locate 
anything — thousands  of  dollars  worth  of  tools  were 
constantly  lost — the  duplicating  of  tools  representing  a 
large  investment,  and  the  tools  were  often  not  in  proper 
condition. 

74.  Their  duty  is  to  pick  out  any  discolored  peas,  for 


132     COMPOSITION  OF  TECHNICAL  PAPERS 

these  spoil  the  looks  of  a  can,  and  at  present  no  means  of 
removing  them  has  been  discovered. 

75.  A  device  has  been  devised  by  Cooper  and  Cooper, 
N.  Y.,  which  furnishes  a  simple  means  of  removing  the 
limitations. 

76.  There  remains  the  argument  against  it  of  requir- 
ing considerable  labor,  necessitating  the  use  of  tongs  to 
turn  up  the  edges,  also  the  need  of  forming  edge  strips 
in  the  shop  when  for  strips  of  the  shape  shown,  a  brake 
would  be  necessary  for  the  forming  of  them. 

77.  Few  people  are  aware  that  out  on  the  northwest 
side  is  the  largest  motion  picture  factory  in  the  world 
and  to  it  it  will  pay  a  visit. 

78.  While  a  shot  shell  does  not  in  the  true  sense  of  the 
term  contribute  to  the  highest  welfare  of  the  world, 
nevertheless  the  processes  employed  by  the  Diamond 
Cartridge  Co.,  Quebec,  Canada,  in  its  manufacture  are 
fairly  interesting. 

79.  It  seems,  therefore,  preferable  to  lay  the  responsi- 
bility of  the  repair  upon  the  shop  foreman  in  the  first 
instance. 

80.  In  reporting  on  this  engine  there  are  two  things  to 
be  considered;  one  is  the  condition  of  the  stoking  machin- 
ery, the  other  being  the  condition  of  the  boilers. 

81.  It  is  arranged  in  such  a  manner  that  eight  men 
can  work  at  the  lathes,  while  others  can  cut  wood  pre- 
paratory to  being  turned. 

82.  If  he  can't  set  his  derrick  on  the  roof  and  must 
leave  it  on  the  ground,  if  the  derrick  is  short  he  will  have 
to  hitch  to  the  stacks  below  the  centre  and  he  must  in 
this  case  tie  a  weight  to  the  bottom  of  the  stack  or  hold 
it.  with  ropes  to  keep  it  upright,  then  when   the  stack 


THE  SENTENCE  133 

is  raised,  have  his  men  take  the  guy  wires  and  pull  it  up 
straight  to  be  let  down  on  the  boiler. 

2>Tf,  Essentially  the  process  consists  of  three  steps, 
drying,  mixing,  and  pulverizing  the  raw  material;  burn- 
ing the  pulverized  material  to  form  clinkers,  and  pul- 
verizing the  clinkers. 

84.  T.  B.  calls  attention  to  a  defect  of  the  gear  hobbing 
machine  that  I  have  not  seen  in  print. 

85.  Limestone  is  almost  universally  employed  and  its 
value  as  a  flux  depends  upon  its  freedom  from  impurities. 

86.  When  a  horse  pulls  a  cart,  then,  if  the  cart  pulls 
back  on  the  horse  an  equal  amount  (as  the  law  states) 
why  is  it  that  they  generally  move  forward? 

87.  An  engineer  who  has  been  trained  for  electrical 
work  may  be  called  upon  at  any  time  to  erect  a  trans- 
mission line,  lay  out  plans  for  a  dynamo  room,  or  one  of 
many  possibilities  that  the  person  hiring  him  could 
very  well  expect  him  to  accomplish. 

%^.  One  man  may  be  very  good  in  subjects  dealing 
with  chemistry;  another  may  lean  toward  civil  engineer- 
ing work  and  the  construction  of  large  structures;  still 
another  may  not  care  for  either  of  the  above-mentioned 
lines  of  work  but  who  would  take  great  interest  in  electri- 
cal or  mechanical  subjects. 

89.  The  construction  of  the  manhole,  the  bumping  of 
the  head,  and  the  method  in  which  the  manhole  is  made 
steam-tight,  were  noted.  Next  the  dry  pipe,  the  baffle 
plates,  and  the  feed-water  pipe  were  observed.  A  large 
amount  of  scale,  pitting,  and  corrosion  on  the  surface 
of  the  drum  was  found. 

90.  The  amount  of  water  and  the  depth  from  which  it 
must  be  lifted  are  the  chief  considerations  in  choosing 
a  pumping  system. 


134    COMPOSITION  OF  TECHNICAL  PAPERS 

91.  They  have  now  been  in  use  some  time  satisfac- 
torily and  we  drill  5  or  6  holes  without  sharpening  and 
the  diameter  shows  no  decrease  from  the  original  length. 

92.  This  has  been  accomplished  by  several  pattern- 
makers through  the  use  of  a  jig  for  forming  the  teeth, 
making  them  of  small  blocks  and  gluing  them  to  the 
gear  blank. 

93.  He  was  only  speaking  of  the  merits  of  the  thing 
and  he  thought  it  was  a  good  thing. 

94.  The  ordinary  mower  is  used,  but  instead  of  leaving 
the  hay  scattered  on  the  field  to  be  raked  into  cocks,  it 
is  placed  in  long  rows  or  windrows  by  an  attachment 
called  the  buncher. 

95.  It  is  circular  in  shape  being  about  four  inches  in 
diameter  and  about  three-quarters  of  a  full  circle  in 
length  and  having  one  end  of  the  tube  closed. 

96.  The  spacing  is  largely  done  by  guess,  and  the 
result  is  usually  a  kink  on  the  first  hot  day,  necessitating 
the  replacing  of  the  damaged  rails. 

97.  This  sewer  was  oval-shaped,  its  vertical  diameter 
being  six  feet  and  its  horizontal  four  feet. 

98.  The  sheeting  consisted  of  eight-inch  planks  placed 
tightly  together  in  a  vertical  position  against  the  sides  of 
the  trench,  stringers,  and  braces. 

99.  Smoke  is  an  indication  of  inefficiency  and  waste, 
and  is  not,  as  is  the  popular  belief,  an  indication  of 
prosperity. 

100.  Second,  the  correct  oil  must  be  used  for  a  specified 
kind  of  work;  as  for  example,  animal  and  vegetable  oils, 
while  good  for  low  speeds,  could  not  be  used  on  steam 
turbines  as  high  speed  causes  foaming  and  a  tendency  to 
decompose  the  metals. 

loi.  A  hollow  steel  casting  known  as  the  water  leg  or 


THE  SENTENCE  135 

saddle  is  riveted  to  the  shell  over  each  orifice,  these  cast- 
ings having  a  width  equal  to  about  three-fourths  of  the 
diameter  of  the  boiler  shell,  a  height  of  about  eighteen 
inches,  a  width  of  six  inches,  and  having  a  thickness  of 
metal  about  one  inch. 

102.  This  mammoth  device  consists  of  a  great  steel 
beam,  technically  known  as  a  bascule  arm,  unevenly 
but  decidedly  balanced  on  the  top  of  a  tall  tower  and 
swinging  into  the  air  to  a  height  of  260  feet  a  double- 
decked  cage  freely  suspended  from  its  longer  arm  con- 
taining as  many  as  114  passengers  at  a  single  trip. 

103.  At  the  rear,  like  a  scorpion,  are  set  the  rake  teeth, 
which  are  curved  and  bolted  to  a  triangular  frame. 

104.  In  it  are  disclissed  the  advantages  of  using  fly- 
wheel equalizers  in  certain  cases,  as  compared  with  two 
other  methods  which  are  mentioned  but  not  described 
in  detail. 

105.  Considering  the  most  common  type  it  consists 
of  a  metal  body  either  brass  or  malleable  iron  depending 
upon  the  conditions  of  operation,  which  is  mouldefl  into 
a  spherical  shape  there  being  elongations  on  the  three 
rectangular  coordinates  of  a  plane  through  the  center,  in 
order  that  the  valve  may  be  connected  to  the  pipe  by  the 
two  directly  opposite  and  to  hold  the  stem  and  gasket 
for  the  raising  and  lowering  of  the  gate. 

106.  The  writer  is  indebted  to  S.  M.  Jones,  Mech. 
Supt.,  for  the  foregoing  details,  who  not  only  directed  the 
work,  but  lived  on  the  job  until  all  danger  of  a  possible 
shutdown  had  been  avoided. 

107.  There  is  a  favorite  line  of  steamboats  making  this 
trip  which  are  favorites  for  those  who  do  not  own  motor- 
boats. 

108.  The  system  and  its  various  parts  are  fully  de- 


136     COMPOSITION  OF  TECHNICAL  PAPERS 

scribed  and  thus  make  the  article  economical  for  thQ 
reader. 

109.  This  is  a  large  tower  about  eighty  feet  high  and 
has  a  maximum  diameter  of  twenty  feet. 

no.  As  the  water  in  the  receiving  tank  lifts  a  float 
ball,  a  valve  is  operated  in  the  governor  chamber,  which 
permits  the  water  to  be  drawn  from  the  receiving  tank 
through  the  governor  until  a  certain  predetermined  level 
has  been  reached,  when  the  valve  closes,  which  opera- 
tion takes  place  before  the  air  can  be  drawn  in  from 
the  pump  cylinder. 

111.  Under  one  side  of  the  foundation  the  soil  had 
settled  due  to  leakage  from  a  water  pipe  near  the  foot  of 
the  foundation  whose  existence  had  been  forgotten. 

112.  We  now  have  both  types  side  by  side,  and  when 
showing  visitors  around,  which  shall  I  refer  to  as  the 
standard  tool,  as  it  was  claimed  for  both  that  each  repre- 
sented the  last  word  in  grinders? 

113.  It  was,  of  course,  desirable  to  utilize  as  much  as 
possible  the  natural  pressure  for  all  domestic  service. 

114.  It  is  always  a  hard  matter  to  get  supplies  into  a 
mountain  country,  so  that  equipment  has  to  be  of  light 
weight,  such  as  picks,  shovels,  mattocks  and  wheelbar- 
rows, drill  steel  and  dynamite. 

115.  A  similar  error  is  introduced  if  an  attempt  is 
made  to  connect  the  pressure  terminals  on  the  line  side 
of  the  current  coils  the  applied  pressure  will  be  too  large 
by  the  line  drop  between  these  points  and  the  load,  again 
making  the  readings  too  large. 

116.  My  information  is  presumably  correct,  as  we  here 
are  comparatively  near  neighbors  to  Montana,  which 
State  adjoins  our  own  although  the  university  at  Missoula 
is  actually  about  one  thousand  miles  from  my  location. 


THE  SENTENCE  137 

117.  Another  very  important  feature  of  this  shell 
bushing  is  that  it  can  be  renewed  when  worn  out  much 
cheaper  than  the  whole  spindle. 

118.  I  was  told  when  I  took  charge  that  the  engine 
was  much  overloaded  and  that  it  had  a  very  bad  pound 
but  that  I  was  not  to  let  that  bother  me  as  there  had  been 
two  men  from  the  factory  trying  to  locate  the  cause  but 
had  gone  away  in  disgust. 

119.  The  motor  starts  as  a  repulsion  type  and  auto- 
matically changes  its  connections  to  become  of  the  in- 
duction type  when  the  motor  reaches  a  certain  percentage 
of  speed. 

120.  Therefore,  when  these  questions  come  before  us 
I  can  view  them,  not  only  from  the  position  of  the  manu- 
facturer, not  only  as  they  apply  to  the  Association  or  its 
activity,  but  I  endeavor  to  place  myself  back  again  to  the 
time  when  I  was  an  apprentice  and  consider  matters  from 
his  point  of  view. 

121.  During  recent  years  a  large  number  of  drainage 
districts  have  been  organized  in  the  Mississippi  River 
valley,  in  which  pumping  is  required. 

122.  It  is  utilized  to  locate  all  cable  conductor  troubles 
except  opens  and  will  locate  dead  shorts,  or  faults  with 
a  very  high  resistance  and  can  be  used  by  linemen  who 
have  a  fair  knowledge  of  electrical  conditions. 

123.  I  presume  he  refers  to  the  use  of  return  sand  cones, 
but,  as  stated  above,  the  use  of  these  cones  only  involves 
the  loss  of  about  2  ft.  of  head  on  85  per  cent,  of  the  total 
pulp. 

124.  "It  was  framed  up,'.'  declared  a  beautiful  young 
woman  who  said  she  was  Mrs.  Annette  Dryden  Stein- 
way,  central  figure  in  the  fraudulent  passport  scandal, 
after  being  arrested  to-day  on  charge  of  assaulting  Mr. 


138    COMPOSITION  OF  TECHNICAL  PAPERS 

Katzer,  a  reporter  for  an  Italian  newspaper,  in  hotel 
Marlborough  early  to-day. 

125.  To  secure  the  special  advantages  which  electric 
service  may  render  possible,  what  modifications  in  his 
processes  and  equipments  will  do  this  is  the  real  problem 
before  the  manufacturer. 

126.  Due  to  the  intermittent  operation,  satisfactory 
operating  data  is  not  available. 

127.  In  designing  the  motors  we  have  kept  them  up- 
to-date  in  every  respect  and  have  added  many  special 
features  such  as,  the  patent  of  the  gas-tight  bearings, 
which  is  really  considered  to  be  the  most  valuable  inven- 
tion of  its  kind  on  two-cycle  motors  of  the  age,  water- 
proof and  spark-proof  commutator  which  is  the  most 
simple  commutator  that  can  possibly  be  manufactured 
and  will  give  much  better  and  surer  service  than  the 
gear-driven  elevated  timer,  with  its  complicated  springs 
and  numerous  small  parts,  the  circuit-breaker  or  timing 
lever  for  reversing,  with  which  you  can  reverse  the  engine, 
and  really  a  boat  can  be  handled  with  the  Pearl-edge 
motors  both  reversing  and  forward  practically  as  well 
as  those  equipped  with  reverse  gears,  etc. 

128.  It  is  predicted  that  more  men  will  be  employed 
in  the  Iron  River  district  in  the  coming  season  than  has 
been  recorded  in  any  former  years. 

129.  After  serving  his  time  in  the  shop,  learning  the 
use  of  the  various  tools  and  how  to  use  them,  he  will 
know  what  he  is  going  for. 

130.  Such  things  as  letting  the  lights  burn  all  day  or 
a  shop  too  hot  or  too  cold  must  be  watched. 

131.  The  illustration  shows  a  dirt  train  being  dumped 
on  the  first  lift,  a  working  trestle  being  erected  close  to 
the  main  trestle. 


THE  SENTENCE  139 

132.  On  this  they  experimented  by  hauling  boulders 
from  the  size  of  24  in.  in  diameter  to  as  large  as  they  could 
handle  and  placed  them  to  make  a  firm  foundation,  then 
put  stone  on  the  top  of  them,  which  made  a  good  road. 

133.  The  appliances  were  not  adapted  to  precise  work 
but  the  result  is  not  very  far  wrong  in  my  opinion. 

134.  In  three  years  one  particular  cover  under  my 
charge  was  lifted  twenty  times  and  the  joint  was  perfectly 
good  still. 

135.  Quite  a  number  of  visitors  did  come  long  distances 
to  see  this  250-hp.  machine,  and  some  comments  were 
made  that  this  was  probably  the  upper  limit  in  size  that 
would  ever  be  made. 

136.  Between  the  stampings,  on  ridges  made  in  the 
metal,  the  trolleys  supporting  the  door  ride. 

137.  A  five- ton  truck,  taking  as  many  as  seven  cars 
at  one  time,  hauled  them  about  sharp  curves  over  half 
a  mile  of  private  tracks  without  difficulty. 

138.  The  steel  frame  is  built  up  into  an  extremely 
rigid  unit,  with  scientific  distribution  of  metal,  using  an 
average  of  from  six  to  eight  cross-channel  reinforcements, 
integrally  gusseted,  completing  a  rigid  foundation  of 
extreme  strength,  particularly  adapted  to  the  use  of 
solid  rubber  tires. 

139.  It  is  announced  that  machinery  and  parts  of  same 
may  be  cleaned  quite  as  satisfactorily  and  perhaps 
cheaper  than  by  the  old  method. 

140.  Pieces  of  timber  running  across  the  truck  are 
grooved  to  fit  the  bars  and  holding  the  bars  apart,  so 
that  the  workmen  can  get  his  hands  under  them  or  pass 
a  leather  loop  around  them  to  lift  with  a  hoist. 

141.  When  a  watch  is  laid  on  a  table  and  one  putting 


I40    COMPOSITION  OF  TECHNICAL  PAPERS 

one's  ear  on  the  table  a  few  feet  from  the  watch,  the 
sound  of  the  watch  running  can  be  heard. 

142.  Sediment  in  the  steam  is  also  detrimental  to 
turbines  because  of  the  greatly  increased  erosion  of  the 
blades,  and  in  some  cases  clogging  them. 

143.  Millwrights  have  a  hard  time  to  level  up  shafting 
after  it  has  been  in  use  for  some  time,  due  to  the  sagging 
of  the  overhead  joist. 

144.  Water  is  pumped  into  the  pit  by  a  4-in.  centrifu- 
gal pump,  taking  the  water  from  the  power  house 
supply  well  and  the  water  enters  the  pit  at  the  ground 
level. 

145.  The  base  of  the  lamp  contains  a  dry  battery,  the 
connections  of  which,  running  upward  through  the  body 
of  the  lamp,  and  raising  the  handle,  forms  a  contact  with 
the  base  of  the  burner,  contact  being  broken  when  the 
handle  is  released. 

146.  For  two-story  dwellings  one  or  more  inside  cold- 
air  ducts  are  used  and  one  cold-air  duct  from  outside 
and  many  cases  only  one  of  the  two  inside  cold-air 
ducts  are  supplied,  but  the  outside  cold-air  duct  in  con- 
nection with  the  inside  air  duct  makes  an  ideal  system. 

147.  This  being  due,  in  the  majority  of  cases,  to  tur- 
bines recently  proved  to  be  extremely  wasteful  and  ineffi- 
cient but  once  thought  to  be  economical  in  the  use  of  water. 

148.  The  American  method  is  preferable  where  the 
depth  of  the  rock  is  greater  than  two  feet  in  depth. 

149.  There  are  few  more  exasperating  things  than 
locking  something  securely  and  then  not  to  be  able  to 
find  the  key. 

150.  When  speaking  on  this  phase  of  the  subject,  three 
illustrations  were  shown  by  me  to  prove  the  points  which 
I  tried  to  make. 


PART  II 

TYPES  OF  TECHNICAL 
EXPOSITION 


CHAPTER  VI 
TECHNICAL  DESCRIPTION 

Introduction  to  Types  of  Technical  Exposition 

It  is  the  aim  of  Part  I  of  this  book  to  set  forth  some  of 
the  general  principles  of  expository  writing,  the  prin- 
ciples governing  the  planning  of  the  whole  composition, 
the  organization  of  the  paragraph,  and  the  construction 
of  the  sentence.  It  is  the  aim  of  Part  II  to  explain  and 
illustrate  some  of  the  more  specific  principles  which 
govern  the  composition  of  the  types  of  exposition  with 
which  engineers  are  most  concerned,  technical  descrip- 
tions, expositions  of  processes,  expositions  of  ideas,  re- 
ports, and  business  letters.  The  suggestions  for  effective 
writing  which  are  given  here  are  not  to  be  understood  as 
representing  a  body  of  formulae  universally  applicable; 
they  are  designed  to  serve  only  as  general  guides,  for 
each  technical  exposition  presents  to  a  certain  extent 
its  own  compositional  problems,  which  must  be  studied 
and  solved  independently.  Content,  plan,  emphasis, 
and  even  details  of  construction  are  to  be  determined  by 
the  object  of  the  exposition  and  by  the  person  or  persons 
to  whom  it  is  addressed  or  for  whom  it  is  designed.  Any 
set  of  specific  principles,  therefore,  should  be  used  as  a 
general  guide, — not  slavishly.    ' 

It  is  not,  moreover,  to  be  supposed  that  in  actual  prac- 
tice the  divisions  between  technical  description,  exposi- 
tion of  processes,  and  exposition  of  ideas  are  as  distinct 

143 


144    COMPOSITION  OF  TECHNICAL  PAPERS 

as  the  treatment  of  the  three  types  in  different  chapters 
here  would  indicate.  As  a  matter  of  fact,  most  exposi- 
tions of  processes  contain  descriptive  material,  and  expo- 
sitions of  ideas  may  contain  both  descriptions  and  ex- 
positions of  processes.  But  because  of  the  differences  in 
content  and  in  the  writer's  specific  aim,  it  is  convenient 
for  purposes  of  explanation  to  consider  the  types  sepa- 
rately. In  practice  the  principles  governing  each  type 
may  be  employed  whether  the  type  stands  alone  or  in 
combination  with  other  types. 

The  Student  Themes  following  the  explanation  of  the 
principles  are  designed  for  class  analysis  and  discussion. 
They  are  not  offered  as  models,  but  represent  work  of  all 
grades  from  bad  themes  to  those  which  are  fairly  good. 
They  have  not  been  arranged  in  order  of  merit.  As 
they  are  meant  only  to  illustrate  the  correct  or  incorrect 
application  of  the  principles  set  forth  in  the  chapter  of 
which  they  are  a  part,  all  minor  errors  of  spelling,  punc- 
tuation, and  sentence  construction  have  been  corrected. 
Excepting  for  their  mechanical  correctness  they  may  be 
taken  as  fairly  representative  of  student  writing.  It  is 
not  expected,  however,  that  they  will  displace  themes 
written  by  members  of  the  class,  which  will,  naturally, 
be  fresher  in  interest.  Wherever  possible,  such  represen- 
tative themes  should  be  multigraphed  and  distributed  for 
class  comment. 

The  Specimen  Expositions  which  follow  the  student 
themes  have  been  selected  from  the  point  of  view  of  their 
suitability  for  class  study;  most  of  them  have,  in  fact, 
been  submitted  to  the  teSt  of  actual  class-room  use.  To 
meet  the  needs  of  such  use  there  have  been  certain 
necessary  limitations  in  selection. 

In  the  first  place,  all  articles  highly  technical  or  other- 


TECHNICAL  DESCRIPTION  145 

wise  difficult  to  understand  have  been  excluded.  It  is 
expected  that  the  specimens  will  be  analyzed  by  under- 
graduates in  all  branches  of  engineering  and  often,  too, 
under  the  direction  of  teachers  who  are  not  themselves 
graduates  of  engineering  colleges.  A  highly  technical 
article,  filled  with  mathematical  demonstrations  and 
difficult  scientific  explanations  would  demand  for  its 
mere  understanding  much  time  which  should  be  given  to 
its  rhetorical  study,  while  it  might  not,  at  the  same  time, 
illustrate  expository  principles  any  better  than  a  much 
simpler  article.  Although  the  application  of  this  prin- 
ciple has  led  to  the  inclusion  of  a  few  "popular  science" 
articles,  it  should  be  observed  that  very  many  of  the 
authors  represented  in  the  selection  are  prominent  scien- 
tists and  engineers  writing  for  technical  audiences. 

Another  principle  of  selection  followed  was  to  reprint 
only  articles  which  possess  some  body,  which  provide, 
that  is,  sufficient  material  for  a  class  exercise  of  at  least 
one  period  in  length.  Although  two  or  three  short  selec- 
tions have  been  included,  for  the  specific  reasons  in- 
dicated in  the  notes  preceding  them,  the  making  of  a 
mere  exhibit  of  short  articles  from  the  technical  journals 
has  been  avoided.  In  carrying  out  this  principle,  more- 
over, the  selections  have  with  one  exception  been  re- 
produced in  toto  as  they  originally  appeared;  to  cut  down 
an  article  by  omitting  parts  which  the  author,  for  good 
reasons,  included,  decreases  its  value  for  the  purposes  of 
rhetorical  analysis. 

Finally,  the  articles  have  not  been  selected  primarily 
for  their  content.  An  attempt  has  been  made  to  secure 
some  variety  in  the  subject-matter,  but  there  has  been 
no  effort  to  include  articles  representing  all  branches  of 
engineering  or  all  possible  varieties  of  exposition.     The 


146    COMPOSITION  OF  TECHNICAL  PAPERS 

manner  of  presentation  was  regarded  as  being  of  more 
importance  for  purposes  of  study  in  a  class  in  English 
composition  than  the  subject-matter.  In  a  study  of 
the  specimens  it  is  important  that  this  point  of  view  be 
maintained  lest  the  attention  of  the  class  be  diverted  to 
the  content  and  away  from  the  compositional  aspects. 
It  is  necessary,  of  course,  that  the  ideas  expressed  be 
understood;  without  such  understanding  rhetorical 
analysis  would  be  impossible.  But  class  time  should  be 
given  to  a  consideration  of  the  manner  in  which  these 
ideas  are  presented  rather  than  of  the  ideas  themselves; 
the  class,  in  other  words,  is  a  class  in  English  composition, 
not  in  engineering. 

Not  all  of  the  specimens  are  models^  in  the  narrow  sense 
of  the  word.  Although  they  are  expected  to  illustrate 
the  principles  explained  in  the  text,  several  are  capable  of 
improvement  in  the  larger  matters  of  whole  composition 
and  paragraph,  and  many  of  the  sentences  are  far  from 
impeccable.  A  thorough  study  will,  therefore,  involve 
a  consideration  of  the  ways  in  which  the  specimen  being 
analyzed  can  be  improved. 

The  brief  note  which  prefaces  each  article  is  not  meant 
to  take  the  place  of  a  thorough  analysis  and  study  on  the 
part  of  the  student,  nor  by  any  means  to  encroach  upon 
the  prerogative  of  the  instructor  to  deal  with  the  material 
as  he  sees  fit;  it  is  designed  merely  to.  suggest  to  the  stu- 
dent who  may  be  using  the  book  undirected  by  a  teacher 
some  of  the  elements  which  might  well  be  observed. 

Principles   of   Technical   Description 

Technical  descriptions  of  machines,  apparatus,  gen- 
erating plants,  and  other  objects  of  interest  to  engineers 
are  usually  expositions  inasmuch  as  the  writer's  funda- 


TECHNICAL  DESCRIPTION  147 

mental  aim  is,  in  the  majority  of  cases,  merely  to  make 
clear  the  appearance  of  the  object  described  and 
sometimes  its  method  of  operation.  He  is,  in  other 
words,  explaining,  and  he  is  not  usually  concerned,  as 
is  the  writer  of  artistic  description,  in  recreating  in  the 
mind  of  the  reader  a  reflection  of  any  emotion  which  the 
object  has  aroused  in  him.  His  primary  aim  is  to  re- 
produce in  the  reader's  mind  a  mental  image  of  the  object 
described,  or  at  least  of  its  essential  features.  His 
secondary  aim,  if  he  is  an  agent  or  a  salesman,  or  enthu- 
siastically interested,  may  be  to  convince  the  reader  of 
the  good  qualities  of  the  thing  which  he  is  describing; 
and  this  aim  may  affect  his  method  of  presentation. 
Obviously  the  best  method  to  follow  in  technical  de- 
scription is  an  actual  exhibit  and  demonstration  of  the 
object  to  be  described;  hence  the  ubiquitous  salesman  and 
his  ''line"  of  samples.  But  in  a  great  many  cases  the 
only  means  of  reaching  the  reader  is  by  writing  to  him 
or  for  him,  of  making  as  clear  to  him  as  possible  at  long 
distance  just  how  a  iriachine  or  a  factory  looks.  The 
writer  must  ordinarily  assume  that  his  reader  is  not  famil- 
iar with  the  object  to  be  described;  he  must  leave  him 
with  a  clear  visualization  at  least  of  its  essential  features. 
It  is  quite  legitimate,  then,  for  the  writer  to  use  any  device 
or  trick  which  will  assist  his  reader  to  see  the  object 
clearly.  The  specific  problems  which  confront  the  writer 
of  technical  description  have  to  do  with  the  methods  of 
creating  an  image  in  the  reader's  mind  and  the  questions 
of  how  much  to  include  and  of  how  to  arrange  the  details 
in  a  given  description. 

In  making  clear  to  the  reader  the  exact  appearance  of 
any  object  no  written  description,  no  matter  how  care- 
fully worded,  can  perform  the  same  office  as  a  photograph, 


148    COMPOSITION  OF  TECHNICAL  PAPERS 

sketch,  or  diagram.  A  graphic  representation  gives,  in 
fact,  a  mental  image  which  might  not  come  to  the 
reader  after  the  perusal  of  pages  of  written  description. 
It  is  natural  for  any  one  who  is  attempting  to  make  clear 
the  appearance  of  a  thing  to  say,  ''See,  this  is  the  way  it 
looks,"  and  then  to  attempt  a  drawing  of  the  object. 
And  just  as  naturally  the  reader  expects  this  to  be  done. 
In  addition  to  assisting  the  reader  to  form  a  correct 
mental  image  of  the  object  being  described  an  illustra- 
tion or  diagram  of  any  sort  provides  a  welcome  relaxa- 
tion from  the  reading.  Few  readers  are  so  constituted 
that  they  can  read  page  after  page  of  difficult  technical 
description,  understandingly,  without  fatigue;  illustra- 
tions provide  relief.  Because,  then,  of  this  twofold  value 
of  illustrations,  no  writer  of  technical  description  should 
fail  to  make  use  of  them  whenever  it  is  serviceable  to  do 
so.  This  does  not  mean  that  short  descriptions  of 
simple  objects  should  be  overloaded  with  unnecessary 
illustration,  or  that  any  article  should  contain  illustra- 
tions which  have  little  or  no  connection  with  the  descrip- 
tion. It  does  mean,  however,  that  the  writer  should 
not  fail  to  use  a  graphic  illustration  wherever  it  will  be 
of  real  assistance  to  the  reader. 

However  valuable  illustrations  of  various  kinds  may 
be,  it  should  be  remembered  that  they  have  limitations. 
There  is  much  that  even  the  best  of  them  cannot  do, 
and  the  worst  of  them  may  actually  mislead  the  reader. 
In  fact,  they  can  seldom,  if  ever,  be  used  without  an 
adequate  accompanying  explanation,  and  the  practice, 
therefore,  of  forgetting  that  they  are  at  best  supplemen- 
tary to  the  exposition  and  of  depending  upon  them  and 
reducing  the  written  explanation  to  an  unintelligible 
minimum  is  pernicious.     To  describe  a  machine  merely 


TECHNICAL  DESCRIPTION  149 

by  showing  a  photograph  or  drawing  of  it  is  but  to  take 
a  single  step  in  the  explanation.  The  reader  wishes  to 
know  what  the  essential  parts  are,  how  they  are  related 
one  to  another,  what  the  method  of  operation  is,  and  a 
score  of  things  which  an  illustration  alone  can  not  give 
him.  The  illustration,  then,  should  ordinarily  be  used 
merely  as  a  convenient  supplement  to  the  accompanying 
exposition.  The  most  which  can  be  done  is,  by  means  of 
letters  and  figures  marking  the  various  details,  to  use  it 
somewhat  as  a  demonstrator  uses  an  actual  machine; 
but  even  in  this  case  the  explanation  must  not  be  lacking, 
A  few  general  suggestions  to  be  followed  in  using  visual 
devices  of  various  kinds  have  already  been  given  in 
Chapter  II.  These  may  fittingly  be  amplified  here  since 
it  is  in  technical  description  more  than  in  any  other  form 
of  engineering  exposition  that  illustrations  are  most  use- 
ful. First  of  all,  if  an  illustration  is  to  be  of  the  most 
service  to  the  reader,  it  should  be  placed  close  to  the 
explanation  to  which  it  belongs,  if  possible  on  the  same 
page  so  that  the  reader  may  look  readily  from  explana- 
tion to  illustration.  An  illustration  should  show  clearly 
the  essential  parts  of  the  object  described.  For  this 
reason  a  schematic  outline  drawing  in  which  compara- 
tively unessential  parts  have  been  omitted  or  unempha- 
sized  is  often  better  than  a  more  complete  illustration. 
All  illustrations  should  be  neat;  a  messy  drawing  may  be 
misleading  or  at  least  displeasing.  Accuracy  is  another 
essential;  a  sketch  which  is  incorrect,  or  out  of  propor- 
tion, or  badly  drawn  may  be  worse  than  none  at  all. 
Illustrations  should  be  set  off  distinctly  from  the  text. 
An  ample  margin  around  a  drawing  is  better  in  appear- 
ance than  a  narrow  one  and  prevents  words  or  phrases 
used  in  connection  with  the  illustration  from  running  into 


1 50    COMPOSITION  OF  TECHNICAL  PAPERS 

those  surrounding  it.  Where  the  drawing  is  at  all  com- 
plicated and  is  referred  to  freely  in  the  accompanying 
explanation,  it  is  well  to  label  the  parts  referred  to  with 
letters  or  figures.  Such  symbols  should  be  orderly  in 
arrangement  and  easy  to  find,  and  should  leave  no  doubt 
as  to  the  detail  of  the  machine  which  they  mark.  A 
tabulated  list  of  symbols  and  parts  beneath  the  drawing 
often  makes  reference  more  easy. 

Another  method  of  assisting  the  reader  to  visualize 
the  object,  a  method  similar  in  its  results  to  the  actual 
use  of  a  graphic  illustration,  is  the  comparison  of  the 
thing  described  to  an  object  or  form  already  familiar  to 
the  reader.  How  often  and  how  naturally  this  is  done 
may  be  seen  from  an  examination  of  terms  in  common 
use,  the  T-square  of  the  engineer,  the  trough  of  a  valley, 
the  S-hook  of  the  machinist.  Such  a  comparison  results 
in  the  reader's  perceiving  in  a  flash,  because  of  his  famil- 
iarity with  the  known  member  of  the  comparison,  the 
general  shape  or  fundamental  image,  as  it  is  sometimes 
called,  of  the  unknown  member.  In  making  use  of  this 
device  the  writer  should  take  two  precautions.  First, 
the  unknown  member  of  the  comparison  should  be  likened 
to  an  object  with  which  the  reader  may  reasonably  be 
assumed  to  be  familiar.  If,  for  example,  the  reader  has 
never  seen  a  fish-hook.  General  Sherman's  famous 
comparison  of  the  Bay  of  Monterey  to  one  of  those 
implements  will  be  quite  lost  on  him.  A  second  precau- 
tion is  that  the  known  member  of  the  comparison  have  a 
form  which  is  reasonably  constant.  To  compare  a  re- 
cording instrument,  for  example,  to  a  clock  does  not 
help  the  reader  a  great  deal  since  clocks  are  of  various 
shapes  and  sizes.  To  compare  an  instrument  to  a  gentle- 
man's open-faced  watch,  however,  gives  the  reader  a 


TECHNICAL  DESCRIPTION  151 

very  tolerable  idea  of  its  general  shape  and  size.  The 
writer  should  not  go  too  far  afield  for  his  analogies. 
A  new  type  of  machine,  unfamiliar  to  the  reader,  may  be 
compared  with  an  older  type  with  which  he  is  familiar. 
Such  a  comparison  does  not  take  the  reader  far  from  the 
immediate  subject. 

Besides  having  the  problem  of  getting  the  reader  to  see 
clearly  the  object  described,  the  writer  of  technical  des- 
cription has  the  problems  of  selection  and  arrangement 
of  the  details  of  the  description.  Where  the  object  to  be 
described  is  very  simple  in  construction,  the  difficulties  of 
selection  and  planning  are  correspondingly  few;  where, 
however,  it  is  a  complicated  piece  of  machinery  or  an  ex- 
tensive manufacturing  plant,  the  problems  may  be  puzzl- 
ing. In  the  suggestions  which  follow  it  is  assumed  that 
the  writer  is  attempting  to  write  merely  a  clear  explana- 
tion and  not  a  persuasive  exposition  or  an  argument. 

The  details  selected  will  depend,  of  course,  largely 
upon  the  length  of  the  description  and  the  complexity  of 
the  object  described.  In  a  short  description  of  a  very 
simple  piece  of  apparatus  thiere  is  very  little  selection 
to  be  made;  practically  all  of  the  parts  can  be  included. 
This  is  not,  however,  true  in  the  description  of  a  com- 
plicated machine.  Here  to  attempt  to  include  every 
screw,  and  pinion,  and  spring,  and  bolt  would  result  in 
the  reader's  getting  anything  but  a  clear  conception  of 
the  machine.  In  patent  office  descriptions  it  is  necessary 
to  be  very  exact  and  detailed;  in  most  other  descriptions, 
however,  it  is  better  to  make  a  careful  analysis  of  the 
object  with  the  view  of  selecting  for  inclusion  in  the 
description  only  the  essential  parts.  A  mere  catalogue 
of  parts  is  not  a  description  any  more  than  a  pile  of  junk 
is  a  machine.     The  writer  should  usually  aim  to  give  his 


152    COMPOSITION  OF  TECHNICAL  PAPERS 

reader  a  mental  image  of  the  whole  object  and  of  the 
parts  which  are  really  essential;  to  attempt  to  do  more 
than  this  is  unwise  unless  the  description  is  long,  detailed, 
and  very  fully  illustrated. 

The  problem  of  arranging  the  parts  of  a  technical 
description  is  more  difficult  than  that  of  determining  what 
to  include.  The  plan  of  the  body  of  the  description 
will  naturally  vary  with  the  subject  and  with  the  specific 
aim  of  the  writer.  Certain  general  principles,  however, 
should  almost  invariably  be  followed,  and  these  will  be 
explained  briefly. 

To  begin  with,  since  the  writer  of  a  technical  descrip- 
tion is  attempting  to  see  each  detail  of  the  object 
described  in  its  relation  to  the  whole  and  to  other  details, 
it  is  naturally  necessary  to  give  first  some  idea  of  the 
appearance  of  the  whole  object  before  plunging  into  a 
description  of  the  parts.  The  necessity  of  doing  this 
may  be  made  clearer  by  a  simple  analogy.  If  a  teacher  of 
geography  were  to  attempt  to  sketch  a  map  of  England 
by  drawing  the  Thames  and  the  Cheviot  Hills  and  a  few 
chief  cities  without  first  drawing  the  general  outlines  of 
the  country,  his  pupils  would  be  quite  unable  to  relate 
these  details  to  the  whole  or  even  properly  to  one  another. 
A  writer  of  a  technical  description  who  begins  with  details 
without  first  giving  an  idea  of  the  general  appearance  of 
his  subject  will  similarly  confuse  his  reader. 

Another  general  principle  which  will  often  be  found 
valuable  is  that  of  giving  at  the  beginning  of  the  de- 
scription a  clear  statement  of  the  operating  principle 
of  the  object  to  be  described  or  of  the  purpose  for  which 
it  was  designed.  With  the  general  operating  principle  or 
the  use  clearly  in  mind  the  reader  is  better  able  to  under- 
stand   the    appearance    and    function    of    the    various 


TECHNICAL  DESCRIPTION  153 

details,  for  he  has  a  key  to  them.  On  the  other  hand,  the 
failure  to  begin  a  description  with  an  explanation  of  the 
operating  principle  very  often  results  in  confusion  or  lack 
of  understanding.  For  this  reason  (as  well  as  for  others) 
the  following  technical  description  is  defective: 

Bee  Exposure  Meter^ 

I.  The  Bee  Exposure  Meter  is  a  small,  nickel-plated,  watch-like 
instrument  used  by  many  amateur  photographers  to  find  the  cor- 
rect length  of  time  to  expose  their  plates  or  films  for  dififerent  in- 
tensities of  light.  2.  Many  plates  and  films  besides  many  valuable 
pictures  can  be  saved  by  the  use  of  this  simple  meter.  3.  It  is 
easy  to  operate,  and  almost  any  person,  regardless  of  his  education, 
can  operate  it  very  successfully.  4.  The  meter  has  about  the  same 
size  as  an  IngersoU  Junior  watch,  but  it  has  no  hands  nor  stem,  a 
dififerent  dial,  and  the  crystal  instead  of  resting  in  a  frame  on  the 
outside  of  the  case  is  loosely  set  in.  5.  In  place  of  the  small  second 
dial  on  the  watch  the  meter  has  a  hole  cut  in  the  d?al,  which  has 
the  right  one-half  covered  with  grey  paper  and  the  other  one-half 
a  movable  disc  so  a  new  portion  can  be  exposed  as  often  as  needed. 
6.  The  numbers  on  the  left  half  of  the  dial  represent  the  number  of 
the  U.  S.  stop  used  in  taking  the  required  picture,  and  the  other 
half  the  time  required  to  change  the  movable  one-half  of  the  small 
circle  to  the  same  shade  as  the  grey  paper.  7.  Around  the  outer 
edge  of  the  front  is  also  a  row  of  numbers.  8.  Those  numbers  on 
the  left  represent  the  speed  of  the  film  or  plate  used,  and  those  on 
the  right  the  time  needed  to  give  the  correct  exposure  for  the  pic- 
ture. 9.  The  back  of  the  meter  is  movable  and  can  be  rotated 
at  the  operator's  will.  10.  The  first  thing  to  do  in  operating  the 
meter  is  to  rotate  the.  back  and  turn  a  new,  unused  portion  of  the 
movable  disc  in  place,  and  time  it  to  see  how  long  a  time  is  required 
to  change  it  to  the  same  shade  as  the  grey  color.  11.  Then  look 
up  the  sensitiveness  or  speed  of  your  film  or  plate  in  the  table  sup- 
plied with  each  meter.  12.  Press  the  thumb  against  the  crystal 
and  the  first  finger  against  the  back  and  rotate  the  outer  portion 
of  the  frame  until  the  number  of  the  speed  on  the  left  hand  side 
of  the  frame  corresponds  with  the  size  of  stop  on  the  left  hand  side 

'  The  sentence  numbers  were  added  for  convenience  of  reference. 


154    COMPOSITION  OF  TECHNICAL  PAPERS 

of  the  dial.  13.  Then  opposite  the  time  on  the  right  side  of  the 
dial  find  the  correct  exposure  for  the  picture  on  the  right  side  of 
the  frame. 

This  description  would  be  very  much  clearer  if  the 
writer  had  explained  at  the  beginning  that  the  Bee  Ex- 
posure Meter  measures  the  intensity  of  light  by  deter- 
mining the  length  of  time  required  to  bronze  an  exposed 
portion  of  white  sensitized  paper  to  a  uniform  fixed 
shade./  With  the  operating  principle  thus  set  forth  the 
present  unintelligible  details  in  sentences  5,  6,  and  10, 
with  the  references  to  the  ''new  portion"  and  "the  same 
shade  as  the  grey  paper,"  would  become  more  under- 
standable. If  the  details  of  the  instrument  are  described 
in  terms  of  the  general  operating  principle, — if,  for  ex- 
ample, the  grey  paper  hemisphere  is  said  to  provide  a 
fixed  shade  and  the  revolving  disc  to  be  the  sensitized 
paper,  a  small  portion  of  which  can  be  exposed  without 
exposing  the  whole,  the  description  will  be  still  clearer 
and  more  compact.  As  it  is  written,  however,  the  writer 
has  approached  his  subject  too  indirectly  and  has  left  too 
much  to  the  reader's  inference. 

Very  often  the  general  appearance  of  the  object,  its 
use,  and  its  operating  principle  may  be  made  parts  of  a 
general  definftion.  Often,  in  fact,  one  of  the  best  ways 
to  begin  a  technical  description  is  in  this  way.  A  defini- 
tion may  be  short, — a  single  sentence  only, — or  it  may 
be  long, — an  entire  paragraph  or  more, — and  developed 
with  considerable  detail.  In  any  case  it  is  not  a  definition 
unless  it  really  defines,  that  is,  unless  it  really  differen- 
tiates the  object  from  others  in  the  same  or  in  a  similar 
class.  The  following  attempt  at  a  definition  is  much 
too  empty  and  shallow:  "A  micrometer  caliper  is  an 
instrument   used   extensively  in   shop  work."     This  is 


TECHNICAL  DESCRIPTION  155 

not  very  much  better  than  the  famous  definition  of 
thunder  as  "a  noise  heard  by  persons  not  deaf."  There 
are  scores  of  instruments  "used  extensively  in  shop 
work,"  and  merely  to  classify  the  micrometer  caliper 
with  them  is  not  going  very  far  toward  giving  the  reader 
an  understanding  of  its  appearance,  specific  use,  and 
principle  of  operation. 

It  will  be  understood  from  the  general  principles  of 
technical  description  which  have  so  far  been  set  forth 
that  the  method  of  presenting  details  which  is  most 
logical  and  psychologically  the  most  sound  is  usually 
that  of  giving  general  ideas  first, — definition,  general 
appearance,  principle  of  operation  and  use, — as  a  basis 
for  an  understanding  of  the  details  which  are  to  follow. 
The  organization  of  these  details  in  the  body  of  the  de- 
scription will,  of  course,  vary  considerably.  In  fact,  every 
object  which  is  to  be  described  must  be  subjected  to  an 
analysis  to  determine  the  best  arrangement  of  details 
for  presentation  in  the  description.  Sometimes  the 
logical  order  readily  suggests  itself.  In  the  description 
of  a  factory,  for  example,  the  best  way  is  usually  to 
follow  the  course  of  the  article  manufactured.  In 
describing  a  hydro-electric  power-plant,  similarly,  the 
writer  will  usually  find  that  the  obvious  plan  to  follow 
after  he  has  given  some  general  idea  of  the  layout  of 
the  plant  and  of  the  size^and  shape  of  the  building,  is 
to  describe  the  dam  and  spill- way,  the  channel,  the  in- 
terior of  the  building,  the  generating  units,  and  finally 
the  transmission  system.  In  descriptions  of  machinery 
it  is  sometimes  well  deliberately  to  explain  how  to  as- 
semble the  machine.  Sometimes  in  describing  a  machine 
in  operation  the  logical  method  is  to  follow  the  power 
from  the  initial  impulse  to  the  work  performed.     Often 


1 56    COMPOSITION  OF  TECHNICAL  PAPERS 

an  analysis  of  the  parts  into  the  stationary  parts  and 
the  operating  parts  will  be  found  useful.  Almost  in- 
variably parts  which  cooperate  in  the  performance  of  a 
definite  operation  should  be  grouped  and  described 
together.  In  all  cases  the  writer  should  be  careful  in 
describing  one  detail  of  his  subject  never  to  refer  to 
another  detail  which  has  not  yet  been  described.  All. 
these  suggestions  for  arranging  the  parts  of  a  technical 
description  are,  it  should  be  remembered,  only  sugges- 
tions. In  every  case  the  writing  of  a  technical  de- 
scription should  be  preceded  by  a  careful  analysis  of  the 
object  to  be  described  with  the  aim  of  determining  the 
surest  and  most  logical  method  of  making  the  object 
clear  to  the  reader. 

The  problems  of  writing  clear  expository  description 
are  very  often  complicated  by  the  added  problems  of 
producing  in  the  reader's  mind  in  addition  to  a  clear,' 
concrete  image  of  the  object,  some  impression  of  its 
beauty,  economy,  utility,  or  other  abstract  quality. 
These  problems  the  salesman  must  deal  with  and  the 
engineer  who  finds  himself  called  upon  to  convince  the 
prospective  granter  of  a  right  of  way  that  a  steel  tower 
is  not  unsightly.  Their  consideration  belongs  properly 
to  a  treatise  on  salesmanship  or  argumentation.  In 
general,  the  writer  who  must  leave  his  reader  with  an 
impression  of  a  definite  quality  possessed  by  the  object 
he  is  describing  should  do  so  by  keeping  this  quality 
uppermost  throughout  the  description.  To  do  this  he 
may  have  to  select  for  especial  attention  those  details 
of  the  object  which  embody  best  the  idea  of  the  particular 
quality  being  emphasized.  The  writer  must  determine 
in  each  case  the  extent  to  which  the  persuasive  or  argu- 
mentative element  is  to  enter  into  the  description. 


TECHNICAL  DESCRIPTION  157 


STUDENT  THEMES 

[These  themes  are  for  class  analysis.  They  are  not 
designed  to  serve  as  models,] 

.1.  The  American  Pedometer 

The  American  Pedometer  is  a  small  watch-like  instrument  car- 
ried by  many  people  to  register  automatically  the  number  of  steps 
they  take  and  indicate  it  by  the  number  of  miles  walked.  It  is 
about  the  size  of  a  silver  dollar  and  about  four  times  as  thick.  It 
is  nickel-plated  and  has  a  white  dial  with  black  numbers  from  one 
to  ten.  It  differs  from  the  looks  of  a  watch  in  that  it  has  only  one 
hand  and  in  place  of  the  ring  in  the  stem  the  pedometer  has  a  small 
flat  hook  so  it  can  be  hooked  over  a  belt  or  vest  pocket. 

When  the  back  of  the  case  has  been  removed,  the  entire  mechan- 
ism of  the  instrument  can  be  seen.  There  is  a  small,  crescent- 
shaped  brass  weight  attached  to  one  end  of  a  lever  and  a  three-leaf 
spring,  which  acts  on  a  small  flat  wheel,  which  is  very  finely  notched 
on  its  outer  edge.  There  is  also  a  small  spiral  hairspring,  which 
keeps  the  weight  at  the  highest  position  of  its  stroke.  Then  also 
there  is  a  snake-shaped  regulator,  which  regulates  the  length  of  the 
step  taken  by  putting  it  on  a  number  corresponding  to  the  person's 
average  step.  There  is  also  a  small  knob  to  turn  the  hand  by  and 
six  small  brass  cogwheels. 

A  person  intending  to  use  a  pedometer  after  knowing  his  average 
step  and  having  set  the  regulator  at  the  proper  place  must  hang  it 
vertically  in  his  vest  pocket  or  on  his  belt  so  that  the  motion  of  his 
body  will  cause  the  weight  to  vibrate  up  and  down.  This  up  and 
down  motion  turns  the  small  notched  wheel  at  the  end  of  the  lever, 
and  this  in  turn  transmits  the  motion  through  a  series  of  cogwheels 
to  the  one  fastened  on  the  hand.  By  the  motion  of  the  body  the 
little  pedometer  automatically  tells  you  how  far  you  have  walked. 

2.  The  Speed  Counter 

In  all  instances  where  it  is  necessary  to  determine  the  number 
of  revolutions  per  minute  that  a  shaft  or  other  object  is  making. 


158    COMPOSITION  OF  TECHNICAL  PAPERS    ■ 

the  little  instrument  commonly  known  as  the  speed  counter  is 
invaluable. 

Most  machines  have  their  revolving  parts  moving  so  rapidly 
that  accurate  counting  with  the  eye  alone  is  impossible.  This  de- 
vice is  therefore  applied  to  the  center  of  either  end  of  the  shaft,  and 
the  revolving  disc  held  with  the  thumb  until  the  second  hand  of 
the  watch,  which  is  held  in  the  other  hand,  reaches  a  point  that  is 
easily  remembered.  The  disc  is  then  released,  and  the  speed 
counter  records  the  revolutions  for  as  long  a  peried  as  is  desired. 
Half  a  minute  is  the  time  usually  taken  as  in  most  cases  it  gives 
sufficiently  accurate  results,  and  the  R.P.M.  can  be  found  by  simply 
multiplying  by  two. 

The  instrument  is  a  simple  contrivance  whose  essential  parts 
are  a  worm  wheel,  mounted  on  a  stem;  a  gear,  bearing  the  movable 
disc  which  meshes  with  the  worm,  and  a  stationary  dial,  usually 
divided  into  one  hundred  equal  parts.  When  the  dial  is  divided 
in  this  manner,  the  speed  ratio  of  the  worm  to  the  gear,  or  the  stem 
to  the  disc,  is  one  hundred  to  one,  which  means  that  for  every 
revolution  of  the  stem,  a  mark  on  the  disc  will  pass  over  one  space 
on  the  dial;  also  for  one  hundred  revolutions  of  the  stem,  the  same 
mark  will  trave\  once  around  the  dial. 

The  mark  is  emphasized  by  having  on  it  a  slight  projection. 
The  raised  portion  enables  the  operator  to  observe  the  progress  of 
the  second  hand  on  the  watch  and  still  count  the  complete  turns 
of  the  disc  by  feeling  it  each  time  that  it  passes  under  his  thumb. 

The  stem  is  supplied  with  a  rubber  tip  so  as  to  make  better  con- 
tact with  the  end  of  the  shaft. 

The  worm  and  gear  are  enclosed  in  a  case  of  which  the  dial  forms 
one  side. 

The  speed  counter  complete  does  not  exceed  five  inches  in  length 
and  measures  only  one  and  one-half  inches  in  the  widest  part.  It 
is  about  the  thickness  of  an  ordinary  watch,  so  it  may  be  conven- 
iently carried  in  the  vest  pocket. 

3.  The  Spacing  Mechanism  of  the  L.  C.  Smith  Typewriter 

There  is  little  essential  difference  in  the  spacing  mechanisms  of 
the  various  makes  of  typewriters.  Only  in  the  refinements  of  these 
mechanisms  do  we  find  real  differences  that  differentiate  one  type 


TECHNICAL  DESCRIPTION 


159 


from  another.  The  special  features  of  the  L.  C.  Smith  Brothers' 
spacing  mechanism  that  would  recommend  it  to  our  use  are  the 
easy  access  of  the  spacing  lever  from  the  keyboard  and  the  constant- 
distance  lever  motion  for  all  widths  of  spacing. 

If  we  study  the  sketch  shown,  it  is  seen  that  the  first  feature 
comes  from  the  shape  of  the  spacing  lever,  which  bends  over  the 
frame  in  such  a  manner  as  to  place  the  handle  just  above  the  key- 
board. 

The  basis  of  the  second  feature  will  be  seen  from  a  study  of  the 
entire  mechanism  of  spacing.  Spacing  is  accomplished  by  a  twist- 
ing motion  of  the  lever,  A,  in  which  the  right  hand  end  is  moved 


SPACrNG   MECHANISr^ 

OP- 

TYPBWfejTCR.. 


back,  away  from  the  reader.  This  lever  extends  through  the  cast- 
iron  frame,  K,  and  carries  at  the  rear  a  small  projection,  B,  which, 
as  the  front  part  of  the  lever  is  moved  from  the  reader,  moves  down 
and  pushes  down  the  pin,  C,  which  slides  in  the  bearing,  D,  and 
engages  the  elbow,  £,  at  its  lower  end.  The  motion  of  the  spacing 
lever  is  thus  transmitted  to  the  elbow,  E,  giving  its  upper  arm  a 
motion  to  the  left.  This  elbow  carries  on  its  upper  arm  a  second 
elbow,  F,  which  is  pivoted  to  the  first  elbow,  and  the  upper  arm  of 
which  engages  the  teeth  of  the  rachet  wheel  on  the  platen  and  thus 
turns  the  platen  until  the  lower  arm  of  the  elbow  catches  in  the 
rachet  wheel  and  stops  the  motion. 

In  order  to  regulate  the  width  of  the  spacing,  a  small  pin  in  the 
upper  end  of  the  elbow,  F,  is  forced  by  a  wire  spring  to  follow  a 
cam,  //,  and  by  changing  the  position  of  this  cam,  the  moment  in 


i6o    COMPOSITION  OF  TECHNICAL  PAPERS 

which  the  rachet  engages  its  wheel  is  fixed.  This  cam  is  on  the 
end  of  a  small,  flat  strip,  which  may  be  moved  back  and  forth  be- 
tween two  screws,  which  work  in  slots  in  the  strip.  The  milled 
nut,  /,  carries  on  its  lower  end  a  pin  which  fits  a  series  of  three 
holes  in  the  frame  under  the  strip,  thus  providing  three  positions 
of  the  cam  for  three  widths  of  spacing  of  the  platen.  A  spring 
under  the  nut  insures  its  permanency  in  the  desired  position.  The 
constant-throw  feature  enters  the  mechanism  in  the  cam,  which 
fixes,  not  the  time  when  the  rachet  action  shall  end,  but  when  it 
shall  begin.  The  result  is  the  ease  that  must  inevitably  follow 
from  an  infinite  number  of  throws  of  the  spacing  lever  through  a 
constant  angle. 

4.  A  Standard  Student  Lamp 

The  university  student  does  the  greater  part  of  his  work  in  the 
evening,  and  thus  is  in  need  of  the  very  best  lighting  arrangement 
that  can  be  obtained.  It  was  for  accomplishing  this  purpose  that 
the  student  lamp  was  devised.  In  appearance  it  is  very  much  like 
a  miniature  of  an  old-fashioned  street  lamp,  if  the  lamp  part  is 
imagined  as  being  pivoted  so  as  to  be  movable  in  a  vertical  plane. 
This  gives  one  a  vague  idea  of  how  the  lamp  looks,  in  that  it  con- 
sists of  three  principal  parts:  the  base,  the  upright,  and  the  lamp 
with  shade  and  socket. 

The  iron  base  of  the  lamp  is  about  five  inches  in  circumference 
at  the  bottom,  and  is  covered  with  green  felt.  In  height  it  is  about 
three  inches,  and  is  built  up  to  a  peak  by  a  series  of  three  smaller 
and  smaller  circular  segments.  This  base  is  covered  by  thin  sheet 
metal  so  as  to  give  it  a  smooth  finished  appearance.  Through  the 
center  of  the  base  is  screwed  a  U-shaped  prong  with  a  one-quarter 
inch  hole  drilled  through  the  upper  part. 

The  upright  consists  of  a  rolled  piece  of  sheet  metal  one-half  an 
inch  in  diameter  and  of  sufficient  strength  to  stand  rigid  and  hold 
the  socket  and  lamp.  It  stands  about  a  foot  above  the  top  of  the 
base,  and  has  its  ends  opened  out  and  bent  into  a  U-shaped  prong 
with  a  hole  drilled  through  similar  to  the  prong  on  the  base.  The 
prong  on  the  lower  end  of  the  rod  and  the  prong  on  the  base  are 
then  sandwiched  together  so  that  their  holes  coincide,  and  a  bolt 
is  slipped  through  this  hole,  and  a  thumb-nut  screwed  on  to  hold 
the  two  pieces  tightly  together. 


TECHNICAL  DESCRIPTION  i6i 

To  the  upper  part  of  the  upright  is  attached  a  smaller  circular 
rod  of  the  same  size  and  shape  as  the  upright,  but  only  about  two 
inches  long.  It  has  a  U-shaped  prong  at  the  bottom  with  a  hole 
through  it,  and  is  fastened  to  the  upper  U  prong  of  the  upright  by 
a  bolt  in  the  same  manner  as  the  lower  end  of  the  upright  was 
fastened  to  the  base.  To  the  upper  end  of  this  smaller  rod  is 
attached  an  ordinary  electric  light  socket  and  lamp  with  the  wiring 
cord  from  the  socket  running  through  the  hollow  upright  and  out 
at  the  lower  U  prong  to  the  circuit  plug.  To  throw  the  light  down 
and  concentrate  it  upon  the  object  that  the  person  is  working  on,  a 
semi-circular  tin  shade,  or  reflector,  is  attached  to  the  lamp  by 
spring  clips  on  a  circular  brass  sleeve,  which  is  slipped  through  a 
hole  in  the  shade  and  riveted  to  the  inside. 

When  assembled,  the  lamp  is  very  convenient  in  that  the  movable 
joints  can  be  bent  in  many  attitudes  and  clamped  in  the  desired 
position  by  means  of  the  thumb-nut. 

5.  Batch  vs.  Continuous  Concrete  Mixers 

Of  the  two  classes  of  concrete  mixers,  batch  and  continuous,  late 
practice  is  favoring  the  batch  mixer  as  the  superior.  A  batch 
mixer  is  one  into  which  a  properly  proportioned  mixture  of  mate- 
rials is  placed,  mixed,  and  discharged  in  a  mass.  A  continuous 
mixer  is  ojie  into  which  the  materials  are  fed  continuously,  and 
which  discharges  them  in  a  continuous  stream.  The  relative  ad- 
vantages of  the  two  classes  will  readily  be  seen  after  a  description 
of  a  general  type  of  each. 

A  batch  mixer  consists  primarily  of  a  hopper,  //,  a  power  driven, 
revolving,  spherical  or  conical  drum,  D,  a  water  tank,  T,  and  a  dis- 
charge chute,  S,  all  arranged  as  shown  in  the  diagram.  To  mix 
concrete,  cement,  sand,  and  stone  are  placed  in  the  hopper  in  their 
proper  proportions.  This  is  then  raised,  and  the  materials  slide 
into  the  drum.  The  engine  is  started,  and  while  the  drum  is  re- 
volving, the  proper  proportion  of  water  is  run  into  it  through  pipes, 
P.  A  series  of  blades  in  the  drum  churns  and  thoroughly  mixes 
the  materials.  This  takes  about  three  minutes,  after  which  the 
chute,  S,  is  lowered,  and  the  concrete  will  discharge. 

A  continuous  mixer  has  a  hopper  containing  three  chambers,  i,  2, 
and  3,  into  which  cement,  sand,  and  stone  are  placed  respectively. 


i62    COMPOSITION  OF  TECHNICAL  PAPERS 

An  opening  in  the  bottom  of  each  chamber  is  so  arranged  that  the 
material  in  it  falls  through  at  a  certain  rate,  thus  forming  the  pro- 


Batch  mixer. 

portioned   mixture.     A  propeller-like .  arrangement  of  blades,   B, 
carries  the  materials  out  through  the  chute,  S.     The  intimacy  of 


Continuous  mixer. 


mixture  depends  upon  the  churning  action  of  the  propeller  blades. 
Water  is  added  by  means  of  pipe,  P. 

The  chief  factor  which  influences  good  concrete  is  the  proper 


TECHNICAL  DESCRIPTION  163 

proportioning  of  materials.  That  we  gain  this  in  the  batch  mixer, 
where  just  so  much  cement,  so  much  sand,  and  so  much  stone  are 
placed  in  the  hopper  and  then  mixed,  there  can  be  no  question.  On 
the  other  hand,  in  the  continuous  mixer,  the  rate  at  which  materials 
flow  through  their  hopper  chambers  depends  partly  upon  their 
depth  in  those  chambers;  the  greater  the  depth,  the  greater  the 
gravity  pressure,  and  consequently,  the  greater  the  flow.  What 
is  to  prevent  a  foreman  whose  interests  are  too  closely  allied  with 
those  of  the  contractors  from  keeping  the  supply  of  cement  rather 
low  in  its  hopper?  Another  factor  that  must  be  considered  is  that 
moisture  might  cause  caking  upon  the  sides  of  the  cement  chamber 
and  partly  close  its  orifice.  The  effect  of  this  upon  the  mixture 
is  obvious.  Thus  we  see  that  in  the  continuous  mixer  we  cannot 
depend  absolutely  upon  the  proper  proportioning  of  material,  as 
we  can  in  the  batch  mixer. 

Another  factor  in  making  concrete  is  the  amount  of  water  used. 
In  the  batch  mixer  a  definite,  predetermined  amount  of  water  is 
allotted  to  each  batch.  This  insures  concrete  of  a  uniform  con- 
sistency. In  the  continuous  mixer,  on  the  other  hand,  water  flows 
upon  the  materials  continuously,  and  the  rate  of  flow  which  gives 
the  proper  consistency  is  largely  a  matter  of  personal  equation  in 
the  operator.  The  results  are  naturally  not  so  reliable  as  the  certain 
ones  of  the  batch  mixer. 

In  the  batch  mixer  the  thoroughness  of  the  mix  depends  upon 
the  number  of  revolutions  of  the  drum.  As  the  drum  can  be  turned 
over  any  number  of  times,  there  is  no  danger  of  insufficient  mixing. 
In  the  continuous  mixer  the  thoroughness  of  mix  depends  upon  the 
length  of  the  mixing  chamber.  If  the  concrete  comes  out  insuffi- 
ciently mixed,  there  is  no  means  of  remedying  this  fact. 

Thus  it  is  clear  that  the  machine  which  under  all  conditions  will 
supply  the  better  and  more  uniform  grade  of  concrete  is  the  batch 
mixer. 

6.  A  Concrete  Mixing  Plant 

When  concrete  is  mixed  in  large  quantities,  the  problem  of  hand- 
ling the  raw  and  the  finished  materials  becomes  a  very  difficult 
one.  As  concrete  weighs  about  one  hundred  and  fifty  pounds  per 
cubic  foot,  a  mixing  rate  of  forty-five  cubic  yards  per  hour  means 
the  moving  of  over  ninety-one  tons  of  material  in  that  time,  which 


i64    COMPOSITION  OF  TECHNICAL  PAPERS 

presents  a  problem  which  even  the  layman  can  see  is  a  very  large 
undertaking. 

The  mixing  plant  which  I  am  about  to  describe  is  now  being 
used  in  the  construction  of  a  dam  across  the  Ohio  River,  about 
sixty  miles  north  of  Cincinnati.  The  plant  is  situated  on  the  north 
side  and  on  the  inside  of  a  coffer-dam,  which  is  now  in  the  river  for 
the  purpose  of  facilitating  the  construction  of  the  dam.  The  top 
of  the  wall,  about  ten  feet  wide,  is  sixteen  feet  above  low  water. 

The  plant  can  hardly  be  called  a  building,  for  it  is  open  on  all 
sides;  yet  it  has  a  lean-to  roof,  for  the  purpose  of  protecting  the 
cement  bags  from  rain.  Although  the  roof  is  of  light  material, 
the  rest  of  the  structure  is  rather  massive,  for  the  building  must 


^a\crj^vt\. 


1.  Roof. 

2.  Storage  bins. 

3.  Column  supports. 


4.  Measuring  boxes. 

5.  Hopper. 

6.  Floor. 


7.  Wall  of  coffer-dam 

8.  Mixer. 

9.  Track. 


General  layout  of  plant. 


support  the  bulky  concrete  ingredients.  The  building  is  divided 
into  three  stories,  the  lower  one  being  on  the  level  with  the  river 
bed,  the  second  one  being  even  with  the  top  of  the  dam,  and  the 
third  extending  above  the  top  of  the  dam.  The  top  story,  which 
consists  of  storage  bins,  one  for  the  sand  and  one  for  the  gravel, 
is  about  the  size  of  half  a  freight  car. 

Small  openings  in  the  bottoms  of  these  bins  connect  the  third 
and  second  stories.  The  second  floor  might  be  termed  the  mixing 
floor,  for  it  is  here  that  the  sand,  gravel,  and  cement  are  mixed. 
Two  measuring  boxes  the  sizes  of  which  were  determined  by  the 
proportions  of  the  mix  are  placed  under  the  openings  from  the 
storage  bins.     These  measuring  boxes  contain  removable  ends,  so 


TECHNICAL  DESCRIPTION  165 

that  the  sand  or  gravel  can  be  quickly  let  down  into  them,  measured, 
and  dumped.  The  mixture  falls  into  a  rectangular  hopper,  which 
if  filled  would  hold  about  a  wagon-load  of  material.  Four  sacks  of 
cement  are  dumped  into  the  hopper,  and  the  charge  is  ready  for 
the  mixer. 

A  signal  is  now  given  to  a  laborer  on  the  first  floor,  who  pulls  a 
lever  which  lets  the  ingredients  down  through  a  chute  and  into  the 
mixer.  This  mixer,  with  a  small  steam  engine  used  to  run  it,  and 
a  cylindrical  can  for  measuring  the  water,  is  about  the  only  thing 
to  be  seen  on  this  floor.  A  steel  track,  having  a  gage  of  three  feet, 
runs  up  to  the  edge  of  the  mixer,  so  that  the  concrete  can  be  dumped 
into  iron  buggies  running  on  this  track. 


7.  The  Atka  Model  Canoe 

In  selecting  a  canoe  I  wanted  one  for  use  on  both  rivers  and  lakes. 
This  meant  one  that  combined  stability  with  ease  of  running 
and  handling,  thus  making  it  equally  useful  on  heavy  seas  and  long 
river  stretches.  I  found  what  I  was  looking  for  in  one  of  the  Old 
Town  Company's  late  canoes,  a  seventeen  foot  Atka  model. 

This  canoe  weighs  seventy  pounds  and  is  wide  enough  at  the 
midportions  to  allow  two  persons  to  sit  in  the  bottom  side  by  side. 
The  central  half  of  the  bottom  is  built  very  flat;  this  gives  the 
canoe  a  light  draught,  which  makes  it  easy  running.  From  this 
portion  the  canoe  is  built,  without  losing  its  graceful  lines,  with 
a  greater  depth  and  a  narrower  beam  at  both  stern  and  bow  ends. 
These  ends  cut  the  water  readily,  and  their  depth  and  width  of 
beam  have  the  efi^ect  of  creating  a  low  center  of  gravity,  causing 
great  stability.  The  ends  come  up  in  graceful  curves,  viewed 
from  the  side,  and  are  decked  over  about  fifteen  inches.  These 
decks  add  greatly  to  the  appearance  of  the  craft.  A  good  feature 
of  the  canoe  is  its  open  gunwales.  The  ribs  come  up  between  two 
strips  of  wood  which  form  the  top  edge,  leaving  alternate  spaces 
and  rib  cross  sections.  This  makes  it  easy  to  keep  the  canoe  clean, 
as  it  can  be  rinsed  thoroughly,  and  every  drop  of  water  can  be 
drained  from  it.  The  advantage  over  the  ordinary  closed  gunwale, 
which  always  prevents  a  little  dirty  water  from  draining  out,  is 
obvious.  Two  horizontal  braces  at  the  third  section,  and  the 
regulation  seats  complete  the  canoe. 


1 66    COMPOSITION  OF  TECHNICAL  PAPERS 

The  canoe  is  made  of  cedar  planking  built  up  around  a  frame  of 
ribs  attached  to  the  bottom  beam  and  the  gunwales.  This  planking 
is  of  select  straight  grain  wood,  and  each  plank  runs  from  one  end 
of  the  canoe  to  the  other  without  a  break.  All  parts  are  nailed 
together  with  small  copper  nails.  The  whole  is  covered  with  stout 
canvas,  which  is  heavily  enameled  with  a  water  proof  marine  paint 
finished  off  with  shellac.  The  inside  is  finished  with  a  light  colored 
water  proof  varnish. 

8.  The   Basement   of   the   Chemical   Engineering   Building 

A  long  hallway  runs  north  and  south,  the  full  length  of  the 
Chemical  Engineering  Building  basement.     This  hall  is  reached 


'teisi  ^"^*^ 


■'yror^etlj 


electric 


liij_gllii^z:_e 


mm 


y< 


i 


-«^*y 


from  the  upper  floors  by  a  stairway  in  the  middle  of  the  building. 
At  the  extreme  north  end  of  the  hall  is  a  door  opening  into  the 
Industrial  Chemistry  laboratory.  This  room  contains,  at  the 
west  end,  two  vacuum  drying  ovens  standing  up  against  the  wall, 
and  a  vacuum  evaporating  kettle  about  ten  feet  out  from  the  wall, 
resembling  a  huge  black  egg  on  legs.  Between  the  two  drying 
ovens  are  a  small  steam  exhaust  pump  and  condenser,  which 
produce  the  reduced  pressure  for  the  three  vacuum  apparatus. 
About  the  middle  of  the  north  wall  is  an  ordinary  galvanized  iron 
drying  oven  about  six  feet  high,  heated  with  steam  pipes  and  having 
natural  draught  only.  In  the  east  half  of  the  room  are  four  filter 
presses  of  small  size  and  representative  of  the  commercial  types  in 
practical  use. 

Proceeding  south  along  the  east  side  of  the  hall,  one  meets  first  the 
janitor's  room,  which  has  a  bench  with  several  vises  attached,  a 


TECHNICAL  DESCRIPTION  167 

small  polishing  lathe,  and  several  cupboards  for  tools;  next  the  fan 
room,  which  has  a  medium-sized  exhaust  fan  for  ventilating  pur- 
poses, and  a  small  steam-driven  air-compressor  for  supplying  air 
under  pressure  to  the  various  places  about  the  building  where  it  is 
required.  Beyond  this  is  a  small  store-room,  a  toilet-room,  and 
then  the  stairway  with  a  photographic  dark-room  beneath.  Beside 
the  stairway  is  a  small  switch-board  and  a  motor-generator  set. 
The  next  two  rooms  are  given  over  to  the  course  in  technical  pyro- 
metry.  In  the  first  of  these  two  stands  a  large  glass  case,  filled 
with  numerous  electrical  measuring  instruments. 

At  the  extreme  south  end  of  the  basement  is  the  electric  furnace 
room.  This  room  has  a  high  ceiling,  as  it  is  beneath  the  large  audi- 
torium on  the  second  floor.  The  circumstance  of  the  high  ceiling 
is  quite  fortunate  in  view  of  the  volume  of  smoke  and  fumes  that  is 
evolved  when  the  furnaces  are  in  use.  Along  the  north  wall  are  a 
number  of  very  large  transformers,  from  which  the  power  is  led  to 
the  furnaces  by  cables  of  about  half  inch  size.  There  are  some 
six  or  eight  electric  furnaces  of  various  types  spread  about  the 
room  in  positions  which  change  from  time  to  time,  according  to 
the  desires  of  whoever  uses  them.  A  stairway  at  the  west  end 
leads  down  into  a  very  dark  and  musty  sub-basement,  used  for 
the  storage  of  such  articles  as  are  found  too  old  and  decrepit  for 
use  even  by  the  Chemical  Engineering  Department. 

As  we  proceed  north  along  the  west  side  of  the  hallway,  we  come 
next  to  the  grinding  room.  On  a  low  platform  in  the  northwest 
corner  of  this  room  are  about  five  or  six  small  crushing  machines, 
mainly  of  the  jaw-crusher  type.  In  front  of  this  is  a  gyratory 
crusher,  standing  upright.  In  the  northwest  corner  are  a  small 
fan  and  a  miniature  tube-mill,  both  belted  to  an  over-head  shaft. 
In  front  of  these  is  a  burr-stone  grinder  for  fine  grinding.  In  the 
southeast  corner  is  the  motor  which  drives  the  crushing  machinery. 

Next  to  the  grinding  room  is  another  store-room,  used  for  the 
storage  of  heavy  chemicals  and  apparatus;  and  beyond  this  an 
enlarged  space,  in  which  stands  the  main  switchboard  for  the 
building,  and  at  the  north  end  of  the  enlarged  space  is  an  outside 
entrance.  The  battery  room  comes  next,  with  a  number  of  rows  of 
lead-storage  cells  in  glass  containers.  After  this  is  another  stairway 
to  the  sub-basement,  and  then  comes  another  store-room,  in  which 
are  kept  the  pure  chemicals,  and  then  another  room  which  is  used 
for  experimental  work,  and  we  are  back  again  at  the  starting  point. 


1 68    COMPOSITION  OF  TECHNICAL  PAPERS 


TECHNICAL  DESCRIPTIONS 

A  Convenient  Method  for  Replacing  Series  In- 
candescent Street  Lamps  ^ 

[The  following  short  description  is  an  example  of  the 
type  of  brief  article  frequently  contributed  by  practicing 
engineers  to  technical  journals, — merely  a  paragraph  or 
two  on  some  apparatus  or  practice  likely  to  be  useful 
to  other  engineers.  The  effective  use  made  of  photo- 
graphs should  be  noted.] 

Where  series  incandescent  street  lamps  are  installed  at  the 
end  of  long  outriggers,  attached  to  unstepped  iron  posts,  it  is  cus- 


FiG.   I. — Construction  of  device  for  replacing  street  lamps. 

tomary  to  replace  burned-out  and  broken  lamps  from  a  tower 
wagon  or  with  a  stepladder.  The  first  method  is  quite  satisfactory 
where  there  are  hundreds  of  such  posts  in  service.  It  frequently 
happens,  however,  that  a  lighting  company  has  only  a  few  of  such 
posts  to  maintain,  and  these  are  often  located  several  miles  from 
the  shop.     In  such  cases  the  cost  of  operating  a  tower  wagon  is 

1  Reprinted  from  the  Electrical  World  for  April  22,  19 16,  by  permission  of 
the  publishers. 


TECHNICAL  DESCRIPTION 


169 


Fig.  2. — Method  of  using  device  to  remove  lamps  from  the  ground. 


I70    COMPOSITION  OF  TECHNICAL  PAPERS 

prohibitive,  and  the  use  of  a  ladder  is  awkward  and  introduces  an 
element  of  danger.  By  means  of  the  device  shown  in  the  ac- 
companying illustrations  the  night  inspector  can  quickly  and  easily 
replace  a  lamp  from  the  ground. 

The  construction  of  the  apparatus  is  shown  in  detail  in  Fig.  i. 
A  pair  of  tongs  is  fitted  with  semi-circular  clasps  that  close  around 
the  lamp  base,  holding  it  rigid  and  allowing  no  lateral  motion. 
These  clasps  press  against  the  top  of  the  base  rim  when  the  lamp  is 
being  removed.  In  returning  the  lamp  to  the  receptacle  a  lug 
on  each  jaw  fits  under  the  rim  and  forces  the  lamp  into  place. 
About  ^^-in.  play  between  the  clasps  and  the  lugs  permits  of  quick 
adjustment  of  the  jaws  in  grasping  the  lamp  base.  It  will  be 
noted  that  no  part  of  the  device  touches  the  lamp  itself,  so  that  it  is 
as  easy  to  remove  a  broken  lamp  as  one  that  is  burned  out  or 
blackened.  The  tongs  in  the  particular  outfit  shown  have  been 
rounded  out  to  allow  clearance  for  lamps  of  the  shape  now  manu- 
factured in  sizes  of  250  cp.  and  over.  The  tongs  are  opened  and 
closed  by  means  of  a  rod  running  the  length  of  the  stick  upon  which 
they  are  mounted.  This  rod  is  attached  to  an  insulated  operating 
lever  at  the  lower  end  of  the  stick.  A  tension  spring  controls  the 
operating  lever  so  that  lamp  base  cannot  be  released  even  if  the 
operator  removes  his  hand  from  the  handle.  The  apparatus  was 
made  at  small  cost  by  a  local  blacksmith,  who  used  the  stick  and 
operating  handle  of  an  ordinary  tree  trimmer  in  its  construction. 
The  writer  has  found  the  device  a  valuable  time  and  trouble  saver. 


The  Mechanical  Filter^ 

Mansfield  Merriman 

[The  following  brief  description  illustrates  the  use  of 
the  diagram  to  assist  the  exposition.  The  value  of  the 
diagram  will  be  at  once  evident  if  the  reader  can  imagine 
the  difficulty  of  visualizing  the  filter  from  a  mere  verbal 
description,  no  matter  how  clear  and  accurate  this  may 
be.] 

1  Reprinted  by  permission  of  the  publishers  from  pages  74-76  of  Elements 
of  Sanitary  Engineering  (John  Wiley  and  Sons,  1909). 


TECHNICAL  DESCRIPTION 


171 


A  mechanical  filter  is  one  that  is  operated  by  power  and  strains 
the  water  at  a  rapid  rate  through  sand  or  other  suitable  material, 
afterwards  discharging  it  into  a  basin,  where  sedimentation  may 
take  place.  Alum  is  often  employed  as  a  precipitant,  this  being 
added  in  the  form  of  a  solution  before  the  water  enters  the  filter. 
Mechanical  filters  are  frequently  used  in  hotels  and  hospitals,  as 
also  for  the  public  supplies  of  towns  and  small  cities. 

The  mechanical  filters  used  in  America  are  quite  similar  in 
principle,  although  they  differ  much  in  detail  and  arrangement. 
In  some  the  water  passes  through  under  the  action  of  gravity,  while 
in  others  it  is  forced  through  by  pumps,  the  former  having  wooden 


Mechanical  gravity  filter. 


tanks  with  an  open  top,  while  the  latter  are  made  of  steel  and  are 
closed.  Rectangular  vertical  tanks  of  concrete  have  been  used 
since  1900  for  the  mechanical  gravity  filters  of  public  water  supplies. 
When  water  is  forced  through  filters  by  pumps,  steel  cylinders  are 
used,  and  these  are  sometimes  arranged  so  as  to  be  reversible  in 
position.  A  general  description  of  the  method  of  operation  of  a 
gravity  tank  will  render  clear  the  principle  of  action  of  all  American 
mechanical  filters. 

Imagine  a  cylindrical  wooden  tank,  say  12  feet  in  diameter 
and  20  feet  high.  The  water  is  brought  into  this  tank  through 
a  pipe  A,  and  by  means  of  an  apron  is  scattered  so  that  it  may 
receive  some  aeration.     Near  the  bottom  of  the  tank  is  seen  a 


172    COMPOSITION  OF  TECHNICAL  PAPERS 

sand-bed,  B,  about  two  feet  thick,  contained  in  an  iron  box  with  a 
perforated  bottom.  The  pressure  due  to  the  head  above  B  forces 
the  water  through  this  sand  to  the  chamber  C,  whence  it  passes 
through  the  pipe  D  to  the  settling  basin.  After  a  time,  varying 
from  six  to  twenty-four  hours,  according  to  the  degree  of  impurity 
of  the  water  under  treatment,  the  sand-bed  becomes  clogged  with 
dirt  and  the  rate  of  straining  is  so  slow  that  the  process  is  stopped 
in  order  to  clean  and  wash  the  sand.  For  this  purpose  the  valve  at 
D  is  closed  and  the  chamber  and  tank  are  drained  by  a  pipe  not 
shown  in  the  figure.  Then  the  valve  E  is  opened  and  water  is 
forced  by  a  pump  into  the  chamber  and  upwards  through  the  sand- 
bed;  simultaneously  the  rake  F  is  lowered  into  the  bed  and  revolved 
by  the  axle  GH,  in  order  to  thoroughly  stir  the  sand.  This  dirty 
water  is  then  drained  off,  and  the  cleaned  bed  is  ready  for  the  next 
operation. 

While  the  above  description  does  not  exactly  represent  any 
particular  mechanical  filter,  yet  it  is  believed  that  it  gives  a  fair 
account  of  the  principles  involved  in  all  of  them  and  of  the  general 
method  of  operation.  A  filter  of  the  size  stated  generally  delivers 
from  300,000  to  400,000  gallons  in  twenty-four  hours,  or  approxi- 
mately at  the  rate  of  3000  gallons  per  square  foot  of  surface  per 
day.  When  arranged  for  the  purification  of  a  public  supply  a 
number  of  them  are  required,  the  pumps  and  machinery  for 
all  being  driven  by  the  same  engine.  There  are  in  the  market  about 
six  principal  styles,  each  having  special  patents  covering  the 
details  of  arrangement  and  methods  of  washing.  In  all  cases  the 
principle  is  that  of  straining,  supplemented  by  frequent  cleaning 
of  the  strainer,  and  the  natural  process  of  removal  of  organic  matter 
by  nitrification  is  imitated  but  slightly. 


Sand-drying   Plant   of   the   Metropolitan   Street 
Railway,  New  York^ 

[The  following  is  an  example  of  the  type  of  explana- 
tion frequently  encountered  in  technical  journals,  the 
description   of   the   plant   or   engineering   construction, 

1  Reprinted  by  permission  of  the  publishers  from  the  Electric  Railway 
Journal  for  April  29,  191 1. 


TECHNICAL  DESCRIPTION 


173 


completed  or  under  way.  Most  of  these  are  elaborately 
illustrated  with  photographs,  sketches,  plans,  and  dia- 
grams. In  the  following  brief  description  the  use  of 
plans  and  the  underlying  process-exposition  involved  in 
the  explanation  of  the  method  of  operation  of  the  plant 
should  be  noted.  A  photograph  has  been  omitted  in 
reprinting.] 

The  Metropolitan  Street  Railway,  New  Yorlj,  dries  all  of  the 
sand  required  for  supplying  the  car  boxes  and  the  sand  cars  operated 
on  the  entire  system  in  a  large  rotary  drier  plant  located  in  the 
basement  of  the  new  carhouse  at  Ninth  Avenue  and  Fifty-fourth 


-83'- i-U-a 


"d 


Grating 


Metropolitan  Street  Railway — Cross-section  through  dry  sand  conveyor. 


Street.  From  200  cu.  yd.  to  300  cu.  yd.  of  sand  is  required  per 
week  during  the  winter  months,  but  the  drier  has  a  guaranteed 
capacity  of  100  cu.  yd.  per  day  of  10  hours,  so  that  ample  reserve 
capacity  has  been  provided.  The  wet  sand  bin  will  hold  1600  cu. 
yd.  and  the  dry  sand  bin  will  hold  700  cu.  yd.  In  addition  to  this 
supply  about  1000  cu.  yd.  is  stored  under  cover  in  a  carhouse  at 
Tenth  Avenue  and  Fifty-fourth  Street.  This  sand  is  available  in 
case  of  emergencies  when  no  fresh  supply  of  wet  sand  can  be  ob- 
tained to  replenish  the  bins  in  the  Ninth  Avenue  carhouse. 

The  sand  used  is  a  fine  sharp  quartz,  free  from  loam,  pebbles  and 


1 74    COMPOSITION  OF  TECHNICAL  PAPERS 

other  foreign  matters.  It  is  dredged  from  the  bottom  of  Long 
Island  Sound  and  is  delivered  on  barges  in  quantities  up  to  500 
cu.  yd.  to  a  convenient  pier  on  the  North  River.  From  the  barges 
the  sand  is  hauled  to  the  Ninth  Avenue  carhouse  in  dump  wagons 
having  a  capacity  of  2  cu.  yd.  each.  These  wagons  and  their 
drives  are  furnished  by  the  maintenance  of  way  department,  which 
keeps  them  at  work  at  other  times  hauling  track  material.  The 
wagons  are  backed  in  on  the  sidewalk  of  Fifty-fourth  Street  and 
the  sand  is  dumped  into  any  one  of  the  seven  openings  in  the  north 
wall  of  the  wet  sand  bin  which  occupies  the  center  of  the  building 
on  the  Fifty-fourth  Street  side  with  the  floor  4  ft.  below  the  level  of 
the  sidewalk. 

The  wet  sand  bin  is  65  ft.  long,  22  ft.  wide,  11  ft.  high  at  the 
back  and  18  ft.  high  at  the  front.  The  sloping  ceiling,  which  is  of 
reinforced  concrete,  forms  the  floor  of  the  dry  sand  bin  above. 
The  floor  is  of  plain  concrete,  6  in.  thick,  and  is  sloped  toward  two 
longitudinal  rows  of  tile  drains  which  discharge  the  seepage  water 
into  the  transfer  table  pit  drains.  The  interior  walls  of  the  bin 
are  formed  of  8-in.  cement-faced  brick  arches,  built  in  between  the 
twin  channel  columns.  The  seven  dumping  doors  in  the  outside 
wall  are  closed  with  rolling  steel  shutters  and  removable  plank 
gates  are  provided  on  the  inside  to  relieve  the  shutters  of  any 
pressure  when  the  bin  is  piled  full.  There  are  no  partition  walls  in 
the  wet  sand  bin. 

A  concrete  tunnel  6  ft.  wide  and  5  ft.  8  in.  high  is  built  under 
the  entire  length  of  the  wet  sand  bin  to  house  the  wet  sand  belt 
conveyor.  Eleven  hoppers  in  the  floor  of  the  bin  discharge  the  wet 
sand  onto  the  conveyor  below.  This  conveyor  has  a  14-in. 
rubber  belt  which  runs  at  a  speed  of  250  ft.  per  minute  when  both 
driers  are  being  run,  and  at  half  that  speed  when  only  one  drier 
is  being  run.  The  belt  is  driven  by  a  22-in.  pulley  on  a  jack  shaft 
which  in  turn  is  belted  to  the  main  countershaft  suspended  from 
the  ceiling  of  the  drier  room.  This  countershaft  is  belted  to  a  40- 
hp.  C.  &  C.  motor  running  at  535  r.p.m.  When  only  one  drier  is 
being  run  the  conveyor  driving  pulley  shaft  is  belted  to  a  second 
jack  shaft  so  as  to  reduce  the  number  of  revolutions  per  minute 
by  half  and  lower  the  speed  of  the  conveyor  to  correspond  with 
the  capacity  of  the  single  drum. 

The  wet  sand  conveyor  discharges  into  a  divided  chute  which 
drops  the  sand  down  into  the  front  ends  of  the  two  rotary  drying 


TECHNICAL  DESCRIPTION 


175 


drums  which  are  mounted  on  the  basement  floor,  20  ft.  below  the 
floor  of  the  wet  sand  bin.  The  drier  room  is  46  ft.  X  34  ft.,  and 
provides  space  for  the  steam-heating  plant  boiler  in  addition  to 
the  two  drier  drums  and  furnaces.  The  heating  boiler  and  drier 
furnaces  are  designed  to  burn  anthracite  pea  coal  and  storage  space 


El. Top  of  Rails  8C.00\ 
Manhole  Eutrauce  to 
Drj  Band  1 


Metropolitan    Street    Railway — Cross-section    through  wet  and  dry 

bins. 


sand 


for  165  tons  is  provided  in  two  vaults  under  the  sidewalk  of  Fifty- 
fourth  Street.  Ashes  are  removed  in  cans  which  are  hoisted  on  a 
hand  elevator  through  a  shaft  opening  onto  the  sidewalk. 

The  sand  driers,  which  were  furnished  by  the  American  Process 
Company,  consist  of  a  furnace  for  burning  the  coal  and  sheet-iron 
cylinder  into  which  the  hot  gases  from  the  furnace  discharge  under 


176    COMPOSITION  OF  TECHNICAL  PAPERS 

forced  drafts.  The  drying  drum  or  cylinder  is  25  ft.  long  and  42  in. 
in  diameter.  On  the  interior  are  riveted  a  number  of  iron  shelves 
which  catch  the  sand  at  the  bottom  of  the  drum,  lift  it  as  the  drum 
rotates  and  drop  it  at  the  top  so  that  it  falls  through  the  blast  of 
hot  furnace  gases.     The  drum  rotates  on  two  steel  tires  which  rest 


Cross  Section 

Metropolitan  Street  Railway — Longitudinal  and  cross-section  of  drier  room, 
showing  driving  shafts. 


on  a  pair  of  rollers  driven  through  bevel  gearing  from  the  main 
countershaft  suspended  from  the  ceiling  of  the  furnace  room.  It 
has  a  slope  of  7  in.  from  the  furnace  end  to  the  dry  sand  end  and 
the  wet  sand  hopper  discharges  into  the  upper  end.  As  the  drum 
rotates  the  sand  is  continuously  raised  and  dropped  through  the 
hot  gases,  and  the  slope  of  the  drum  is  suflBcient  to  cause  the 
sand  to  work  its  way  slowly  out  to  the  discharge  end.     The  rate  of 


TECHNICAL  DESCRIPTION  177 

drying  is  regulated  by  varying  the  volume  of  hot  gases  sent  through 
the  drum  by  the  blast  fan.  This  fan  is  mounted  under  the  ceiling 
of  the  furnace  room  and  is  belt  driven  from  the  main  countershaft. 
The  blast  is  controlled  by  slide  dampers  in  the  pipes  leading  to 
each  furnace.  Either  drum  may  be  rotated  independently  of  the 
other  by  means  of  clutches  on  the  bevel-gear  driving  shaft. 

The  two  drums  project  15  in.  into  a  concrete  flue  chamber  10  ft. 
high  and  4  ft.  9  in.  deep  at  the  discharge  end,  and  the  dry  sand 
falls  into  a  sloping  hopper  which  carries  it  down  to  the  hood  of  the 
dry  sand  elevator.  The  gases  are  carried  off  from  this  chamber 
through  breeching  which  connects  with  the  stack  in  southeast  corner 
of  the  furnace  room.  The  dry  sand  elevator  is  a  lo-in.  belt  carrying 
buckets  8  in.  X  5  in.  spaced  24  in.  apart  and  running  at  a  speed  of 
232  ft.  per  minute.  It  lifts  the  sand  to  the  level  of  the  second 
floor  of  the  carhouse  and  discharges  it  over  a  screen  onto  the  dry 
sand  conveyor,  which  distributes  it  to  the  dry  sand  bin.  The 
distributing  conveyor  is  a  12-in.  belt  running  at  a  speed  of  150  ft. 
per  minute.  It  is  housed  in  a  dirt-proof  casing  built  in  between 
two  storage  tracks  on  the  second  floor  of  the  carhouse  and  extends 
the  full  length  of  the  dry  sand  bin.  Continuous  openings  15  in. 
wide  and  covered  with  coarse  screens  allow  the  sand  to  drop 
through  into  the  bin  from  the  spouts  of  the  automatic  tripper 
on  either  side  of  the  conveyor  track.  The  elevating  and  dis- 
tributing conveyors  are  both  driven  by  a  6.8-hp.  motor,  running  at 
816  r.p.m.j  which  is  mounted  on  the  floor  near  the  elevator  head. 
Special  care  was  taken  in  installing  the  dry  sand  conveyors  to  in- 
close them  in  dust-proof  coverings  so  as  to  prevent  fine  dust  and 
grit  from  being  liberated  on  the  second  floor. 

On  the  first  floor  a  sand  car  loading  track  is  built  along  the 
inside  wall  of  the  wet  sand  bins,  and  collapsible  spouts  with  under- 
cut gates  are  placed  at  intervals  of  11  ft.  6  in.  in  the  bottom  of 
the  dry  sand  bin  wall.  These  spouts  are  designed  to  discharge  the 
sand  through  the  window  openings  of  the  sand  cars,  and  they  are 
spaced  so  that  two  spouts  can  discharge  simultaneously  into  both 
ends  of  a  car.  The  loading  track  will  accommodate  six  cars  at 
a  time. 

The  plant  requires  one  fireman,  one  laborer  and  a  helper  to 
operate  it  at  its  full  capacity.  One  or  both  driers  are  operated 
for  a  full  day's  run  for  two  to  four  days  per  week,  according  to 
the  demand  for  sand.     During  May,  June  and  July,  1910,  868  cu. 


1 78    COMPOSITION  OF  TECHNICAL  PAPERS 

yd.  of  sand  was  dried  at  a  cost  of  15.87  cents  per  cubic  yard.  The 
labor  charge  for  two  men  at  $2  per  day  and  one  man  at  $1.75  per 
day  was  $65.35,  and  57,590  lbs.  of  coal,  costing $2.80  per  gross  ton  of 
2240  lbs.,  was  burned.  The  total  cost  of  operating  the  plant  for 
the  three  months  was  $137.77. 

The  plant  is  operated  under  the  direction  of  H.  H.  Adams, 
superintendent  of  rolling  stock  and  shops  of  the  Metropolitan 
Street  Railway. 

The  Electric  Burglar-alarm^ 

[Although  written  nearly  forty  years  ago,  the  following 
article  is  a  good  example  of  a  simple  and  clear  technical 
description  of  a  popular  sort.  Some  of  the  expository 
elements  to  be  noted  are:  (i)  the  enumeration  of  parts 
at  the  beginning,  (2)  the  logical  arrangement  and  clear 
division  marks,  (3)  the  use  of  illustrations  to  make  clear 
the  appearance  and  operation  of  the  instrument,  and 
(4)  the  inclusion  of  details,  like  that  of  cost,  likely  to  be 
of  interest  to  the  general  reader.] 

Elaborate  as  are  the  ordinary  agencies  for  the  protection  of 
property,  they  afford  but  a  partial  security.  Well-lighted  streets, 
careful  watchmen,  numerous  policemen,  and  strong  and  ingeniously 
arranged  bolts  and  bars,  are  certainly  obstacles  not  easily  over- 
come. But,  in  his  quest  of  other  men's  riches,  the  accomplished 
burglar  has  not  found  them  insurmountable.  However  extensive 
and  vigilant  a  police  force,  it  can  not  have  all  points  under  its 
surveillance  at  once,  and  this  gives  the  burglar  the  opportunity 
which  he  rarely  fails  to  improve.  Bolts  and  bars  are,  doubtless, 
good  things  in  their  way;  but  the  experienced  cracksman  has  a 
cunning  beyond  them.  In  the  contest  between  him  and  the  lock- 
smith, the  victory  has  not  always  been  with  the  latter,  though  he 
has  produced  that  marvel  of  skill  and  workmanship — the  modern 
safe-lock.     The  burglar's  tools  are  not  such  as  are  thwarted  by 

1  Reprinted  from  Popular  Science  Monthly,  Vol.  XVIII  (1880).  p.  56.  by 
permission  of  the  publishers.  The  use  of  the  article  was  suggested  by  Ful- 
ton's Expository  Writing  (Macmillan,  1912). 


TECHNICAL  DESCRIPTION  179 

nice  mechanical  combinations.  Explosives  and  the  simple  mechan- 
ical powers  in  his  hands  have  a  wonderful  range  of  utiUty,  and  are 
able  to  frequently  set  at  naught  the  most  elaborate  contrivances. 
The  protection  afforded  by  these  combined  agencies  is,  however, 
only  realizable  to  its  full  extent  in  the  business  centers  of  large 
cities.  In  residence  districts,  and  in  suburban  and  country  situa- 
tions where  policemen  are  often  few  and  far  between,  reliance  has 
chiefly  to  be  placed  upon  fastenings;  and  these  often  prove  insuffi- 
cient. Yet  it  is  especially  important  for  the  owner  of  property  that 
his  protection  be  good,  for  recovery  is  very  difficult.  The  advan- 
tages are  so  largely  with  the  thieves,  that  they  can  frequently  make 
the  search  a  long  and  costly,  and  often  a  fruitless  one.  The  cost  is, 
in  fact,  the  main  bar  to  recovery.  Only  when  stolen  property  is  of 
large  values  does  it  pay  to  regain  it.  Small  amounts,  such  as  are 
usually  taken  from  private  houses,  are  practically  irrecoverable. 

No  practical  extension  of  the  ordinary  agencies  can  greatly 
increase  present  security.  Bars  and  bolts  have  now  approached 
very  closely  to  their  limit  of  strength  and  ingenuity,  and  police 
surveillance  is  as  extensive  and  perhaps  as  effective  as  circum- 
stances will  permit.  Greater  protection  must  be  sought  in  some 
furthe'r  agency — one  that  will  reproduce  as  nearly  as  possible 
the  condition  of  watchfulness  present  in  the  daytime.  This 
the  electric  burglar-alarm  is  designed  to  do,  and  does  with  a  good 
degree  of  success.  In  its  earlier  forms  there  were  many  defects, 
but  in  a  development  of  twenty  years  these  have  been  mostly 
corrected.  It  has  now  attained  a  simplicity  of  construction  and  a 
certainty  of  action  that  make  it  one  of  the  most  useful  and  trust- 
worthy of  man's  servitors.  Though  widely  known  and  appre- 
ciated both  in  this  country  and  abroad,  there  are  probably  many 
not  acquainted  with  it,  to  whom  a  brief  description  will  not  be 
without  value. 

However  the  details  of  construction  may  differ,  the  essential 
elements  of  every  system  are:  a  bell  to  give  the  alarm,  an  an- 
nunciator to  indicate  the  point  from  which  it  proceeds,  wires 
from  all  the  openings  of  a  building,  and  a  battery  to  furnish  the 
current.  The  elements  are  combined  in  various  ways,  depending 
upon  the  special  circumstances  of  the  particular  case,  but  the 
manner  of  use  is  practically  the  same. 

The  main  piece  of  apparatus,  remarkable  alike  for  the  sim- 
plicity of  its  construction  and  the  range  of  its  performance,  is 


1 80    COMPOSITION  OF  TECHNICAL  PAPERS 

the  annunciator.  In  the  earUer  forms  of  the  alarm  the  indica- 
tions were  made  by  means  of  a  simple  switchboard  provided 
with  buttons  bearing  the  names  of  the  apartments  protected. 
When  an  alarm  sounded,  the  depression  of  each  of  these  buttons 
in  turn,  until  the  bell  ceased  ringing,  was  necessary  to  deter- 
mine its  locality.  This  is  still  quite  largely  used,  as  it  is  cheaper 
than  the  more  perfect  annunciator,  which  tells  at  a  glance  where 
the  disturbance  in  the  circuit  is.      In  shape  and  size  this  latter 


Fig. 


instrument  resembles  an  ordinary  mantel-clock.  The  indica- 
tions are  given  by  devices  on  the  face,  which  vary  with  different 
makers.  In  one  form  they  are  made  by  arrows,  which  lie  hori- 
zontal when  in  normal  position,  and  pomt  to  the  names  of  the 
apartments  printed  above  them  when  indicating.  In  another 
form,  cards  drop  down  in  front  of  apertures  arranged  in  rows  on 
the  face  and  in  still  another  the  name  and  number  of  a  room  are 
uncovered  by  a  falling  piece  when  an  alarm  is  sounded.  The 
needle-instrument  is  shown  in   Fig.  i.     Once    made,    the  indica- 


TECHNICAL  DESCRIPTION  i8i 

tions  remain  until  the  parts  are  restored  by  some  one.  A  small 
switch  at  one  side  completes  or  opens  the  circuit  through  the 
instrument,  and  one  on  the  other  side  controls  the  connection 
with  the  bell.  A  row  of  studs  at  the  base  of  the  apparatus  allows 
any  opening  to  be  disconnected  that  may  be  desired.  Aside  from 
its  giving  an  alarm  when  an  attempt  is  made  to  enter  a  building, 
the  annunciator  has  an  important  use  in  showing  whether  a  place 
is  properly  closed.  If  any  window  or  door  has  been  forgotten,  it 
will  infallibly  point  it  out.  In  large  business  houses  where  there 
are  many  openings,  this  feature  is  of  the  greatest  value.  By  dis- 
connecting the  bell,  this  test  can  be  made  a  silent  one. 

The  mechanism  operating  the  indicators  is  of  the  simplest 
description.  In  the  needle-instrument,  an  arm  on  the  pivot  of  the 
needle  is  held  in  position  by  the  hooked  end  of  a  lever,  the  other 
end  of  which  forms  the  armature  of  an  electro-magnet.  The 
connection  between  the  lever  and  the  supported  arm  is  very  slight, 
so  that  a  small  movement  of  the  former  allows  the  latter  to  fall. 
When  the  circuit  is  closed  this  takes  place.  The  armature  in 
moving  toward  the  magnet  raises  the  hook  end  of  the  lever,  releasing 
the  arm  which  drops  and  turns  its  needle.  In  the  instrument  using 
the  card,  the  card  is  carried  on  the  end  of  an  arm  held  up  in  a 
similar  manner  by  a  hook  on  the  armature  of  the  magnet.  The 
depression  of  the  armature  allows  the  arm  to  drop  by  its  weight. 
The  restoring  of  the  arms  to  position  is  done  by  a  sliding  frame  raised 
by  a  handle  or  button  on  the  base  of  the  instrument.  Delicate  as 
the  movements  of  the  apparatus  are,  it  is  not  easily  put  out  of  order. 
The  points  of  contact  of  the  hook  and  arm  are  so  made  as  to  reduce 
the  wear  to  a  minimum.  The  mechanism  is  all  inclosed,  and  the 
exposed  parts,  such  as  the  needles,  switch-handles,  etc.,  iSnished  in 
polished  metal.  The  annunciator  and  bell  are  usually  combined 
into  one  piece  of  apparatus,  but  they  may  be  put  up  separate  when 
desired. 

This  secures  the  proper  resetting  of  the  apparatus  in  readi- 
ness for  a  new  alarm.  The  result  is  obtained  very  simply  by 
making  the  clapper  turn  a  switch,  which  cuts  from  the  circuit 
the  open  window  or  door,  and  allows  the  current  to  pass  directly 
from  the  battery  to  the  bell. 

The  door  and  window  attachments  for  closing  the  circuit  by  the 
movements  of  these  parts  are  of  various  forms.  Those  used 
on  doors  are  simply  little  push-ping  placed  in  the  casing.  The 
12 


1 82    COMPOSITION  OF  TECHNICAL  PAPERS 

pin  slides  in  an  insulated  case  provided  with  metallic  strips.  When 
it  is  pressed  in,  the  contact  between  it  and  the  strips  is  broken 
and  the  circuit  opened.  When  the  pressure  is  released,  the  pin 
springs  out,  closing  the  circuit.  The  slightest  movement  of  a  door 
allows  this  motion  of  the  pin  to  take  place.  In  one  form  the  pin 
and  a  metalUc  strip  are  so  arranged  that  the  attempt  to  keep  the  pin 
pushed  in,  when  the  door  is  opened,  by  inserting  a  knife-blade, 
establishes  the  circuit  and  gives  the  alarm.  These  push-buttons 
may  be  constructed  to  close  the  circuit,  either  by  pushing  in  or 
springing  out,  and  in  both  forms  have  a  great  variety  of  uses. 
They  may  be  placed  under  the  carpet,  in  the  hall,  on  the  stairs,  in 
front  of  a  window,  or  wherever  any  one  entering  would  be  liable  to 
step.  A  sufficient  number  properly  disposed  could  make  intrusion 
without  giving  alarm  simply  impossible.  The  window  attach- 
ments are  usually  simple  springs  placed  in  the  casing  so  that  the 
movement  of  the  sash  presses  them  together.  One  form  consists 
of  a  roller  on  the  end  of  a  spring  arm,  which  keeps  it  pressed  out 
from  contact  with  a  metal  strip,  through  which  the  circuit  is  com- 
pleted. Placed  in  the  casing,  the  roller  stands  out  and  is  received 
in  a  pocket  in  the  edge  of  the  sash,  so  that  the  motion  of  the  sash 
brings  the  roller  arm  and  metal  strip  into  contact.  For  the 
purpose  of  ventilation  the  pocket  in  the  upper  sash  is  usually 
elongated  to  give  a  free  movement  through  any  desired  distance. 
When  the  lower  sash  is  left  open,  security  can  be  gained  by  cover- 
ing a  push-pin  in  the  window-sill  with  a  flower  pot  or  other  obstruc- 
tion, the  removal  of  which  is  necessary  to  gain  entrance.  The 
wires  forming  the  circuit  are  of  insulated  copper,  carefully  put  up 
so  as  to  be  completely  hidden  from  view.  They  are  run  in  grooves 
in  the  wood-work,  carried  beneath  a  floor,  or  on  its  surface  accord- 
ing to  circumstances.  Once  in  place,  they  remain  unchanged  for 
any  period,  causing  neither  trouble  nor  expense. 

The  Le  Clanch^  battery  is  the  one  universally  employed  with 
this  apparatus.  It  is  very  simple  in  construction,  exhales  no 
noxious  gases  when  in  operation,  does  not  waste  the  material 
when  no  current  is  passing,  and  needs  but  very  little  attention. 
The  positive  pole  is  a  piece  of  gas  carbon  placed  in  a  porous  cell 
filled  with  coarse-grained  peroxide  of  manganese  and  carbon. 
The  cell  is  sealed  at  the  top  with  pitch,  and  a  lead  cap  on  the  carbon 
receives  the  wire.  The  negative  pole  is  formed  with  a  rod  of 
amalgamated  zinc.     Both  poles  are  immersed  in  a  solution  of  sal- 


TECHNICAL  DESCRIPTION 


183 


ammoniac  contained  in  a  glass  jar.     Four  of  these  elements  put 
up  in  a  wooden  case  constitute  the  battery  usually  furnished. 

The  bell  used  is  that  common  with  different  forms  of  electrical 
instruments.  It  consists  of  a  gong  and  a  clapper  vibrated  by  the 
combined  action  of  an  electro-magnet  and  spring.  The  magnet, 
when  the  current  passes,  draws  the  clapper  to  itself  and  in  doing 
so  opens  the  circuit;  this  destroys  its  magnetism  and  allows  the 


Fig.  2. 


spring  to  carry  the  clapper  back.  This  "make"  and  "break" 
action,  rapidly  repeated  as  long  as  the  current  is  passing,  produces 
a  continuous  ringing  of  the  bell.  Reference  to  Fig.  2  will  make 
this  movement  clear.  One  end  of  the  wire  of  the  coils  of  the  magnet 
M  M  is  secured  to  the  binding-post  B,  and  the  other  to  the  post  C. 
The  arm  of  the  clapper  ^  is  a  rather  stiff  spring,  which  in  its  normal 
position  holds  the  armature  e  carried  by  it  from  the  poles  of  the 
magnet.     It  then  presses  against  the  spring  r,  attached  to  the  post 


i84    COMPOSITION  OF  TECHNICAL  PAPERS 

D.  The  post  A  and  E  holding  the  wires  from  the  battery  are 
respectively  connected  with  B  and  D  by  metallic  strips.  The 
current  enters  at  A,  traverses  the  coils  of  the  magnet  M  M,  passes 
through  the  armature  e,  and  out  by  way  of  spring  r  and  posts  D  and 

E.  In  doing  so,  the  soft-iron  cores  of  the  magnet  are  magnetized 
and  attract  the  armature  e.  This  in  moving  breaks  its  contact 
with  the  spring  r,  and  interrupts  the  current.  The  clapper  then 
springs  back  into  position.  In  the  bell  now  generally  used  the 
ringing  continues  not  only  while  the  door  or  window  is  open,  but 
until  the  indicating  parts  of  the  annunciator  are  restored  to  position. 

These  appliances  provided,  the  most  common  way  of  using 
the  system  is  to  make  it  complete  in  each  building,  the  alarm 
apparatus  being  placed  in  a  sleeping  appartment  in  a  private 
house,  and  in  the  watchman's  room  in  a  place  of  business.  So 
arranged,  the  condition  of  the  circuit  is  this:  In  the  daytime, 
when  the  doors  and  windows  are  open,  the  circuit  is  continuous 
at  all  points  except  at  the  alarm  apparatus.  At  night  this  is 
reversed,  the  circuit  being  closed  at  the  instrument,  and  broken 
at  all  the  points  protected.  A  movement  at  any  of  these  points 
which  closes  the  circuit  gives  the  alarm  and  turns  the  proper 
needle  in  the  annunciator.  The  connection  with  the  alarm  is 
made  at  night  by  an  attendant,  and  broken  at  any  desired  time 
in  the  morning.  In  private  houses  fitted  with  electric  bells,  a 
clock  is  often  provided  that  disconnects  the  alarm  in  the  morn- 
ing and  turns  the  current  on  to  a  bell  placed  in  the  servants' 
rooms.  The  movement  by  which  this  is  done  is  something  similar 
to  that  of  the  ordinary  alarm  clock. 

The  protection  afforded  by  such  apparatus  in  good  working 
order  is  probably  as  perfect  as  it  can  be  made.  It  is  generally 
impossible  to  cut  the  wires  from  the  outside  of  the  building,  and 
unless  this  is  done  intrusion  will  start  the  alarm.  Even  if  the 
Nvires  be  cut,  buttons  under  the  carpet  or  circuit-closers  in  interior 
doors  will  reveal  the  burglar's  presence  in  perhaps  every  case. 

Valuable  as  is  the  protection  in  any  particular  case  of  attempted 
robbery,  the  general  immunity  from  such  attempts  that  the  pres- 
ence of  the  apparatus  secures  is  of  still  greater  moment.  Burglars 
will  not  generally  take  such  risks  as  those  imposed  by  an  efficient 
alarm  system,  and  will  therefore  give  a  house  so  protected  a  wide 
berth.  The  only  case  in  which  there  is  room  for  failure  of  the  sys- 
tem is  when  the  battery  power  is  not  suflBcient  to  operate  the  alarm. 


TECHNICAL  DESCRIPTION  185 

But  it  is  a  very  simple  matter  to  provide  against  this.  Tests 
once  every  month  or  two,  and  the  experience  soon  gained  in  using 
the  battery,  will  enable  one  to  know  at  any  time  the  state  of  the 
system.     None  of  the  other  parts  need  ever  cause  any  solicitude. 

While  in  the  great  majority  of  cases  the  plan  of  giving  the 
alarm  to  some  one  in  the  building  broken  into  affords  perfect 
security,  in  some  it  does  not.  In  business  centers,  determined 
and  cunning  burglars,  accustomed  to  take  large  chances,  might 
frequently  overpower  the  watchman  and  stop  the  alarm  before 
it  excited  outside  attention.  To  meet  this  difficulty  the  plan  is 
sometimes  adopted  of  making  the  alarm  sound  in  a  central  ofiBce 
of  the  company  furnishing  the  apparatus.  One  company  doing 
this  has  adopted  a  system  that  seems  to  be  beyond  circumven- 
tion. Each  building  protected  is  connected  on  a  closed  circuit 
with  the  central  office,  at  which  place  delicate  galvanometers 
are  used  as  indicators.  The  circuit  of  each  building  is  independ- 
ent of  all  others.  Any  change  in  the  resistance  of  any  circuit 
is  instantly  shown  by  the  deflection  of  the  proper  needle,  and 
an  alarm  started.  The  opening  of  a  protected  door  or  window 
breaks  the  circuit,  as  does  the  cutting  of  the  line,  and  of  course 
gives  an  alarm.  If  the  burglar  could  carry  the  wire  to  the  ground 
and  insert  just  the  proper  resistance,  no  signal  would  be  given 
at  the  company's  office,  but  this  is  impossible,  as  the  resistance 
is  not  only  that  of  the  wire  but  of  the  apparatus  in  circuit.  The 
only  way  to  get  around  it  is  to  tunnel  under  the  building,  but 
even  then  circuit-breakers  judiciously  disposed  would  generally 
lead  to  detection.  Nothing  is  gained,  so  far  as  the  safe  is  con- 
cerned, in  this  case,  as  it  is  independently  protected.  It  is  placed 
in  a  light  wooden  cabinet  lined  with  a  metallic  casing,  consisting 
of  two  sheets  of  tin-foil  insulated  from  each  other  by  a  thin  sheet  of 
non-conducting  material.  The  wires  from  a  battery  are  con- 
nected each  with  one  of  the  sheets  of  foil.  So  delicate  is  the  insula- 
tion that  the  sticking  of  a  pin  in  the  cabinet  closes  the  circuit  and 
deflects  the  needle,  and  sounds  the  alarm  in  the  central  office. 
This  system,  though  not  yet  in  extensive  use,  is  gaining  in  favor 
among  merchants  having  valuable  stores  of  goods.  A  similar 
plan  of  protecting  private  houses  whose  occupants  are  away  is 
practiced  to  some  extent.  The  apparatus  used  in  this  case  is  much 
less  delicate,  and  the  protection  therefore  not  so  good. 

The  cost  of  applying  the  burglar-alarm  to  any  house  will  vary 


i86    COMPOSITION  OF  TECHNICAL  PAPERS 

in  each  case.  It  depends  upon  the  size  of  the  annunciator  re- 
quired and  the  number  of  openings  to  be  protected.  The  prices 
charged  by  the  different  American  manufacturers  differ  very  little. 
Annunciators  range  in  price  from  thirty  dollars  with  four  indica- 
tions to  one  hundred  dollars  with  twenty.  The  annunciator 
used  should  have  as  many  indications  as  there  are  rooms  pro- 
tected. The  cost  of  circuit-closers,  including  the  placing  in 
position  and  laying  the  wire,  is  three  dollars  a  window  when 
both  sashes  are  connected.  The  same  devices  for  doors  vary 
from  one  and  a  half  to  two  and  a  half  dollars.  In  ordinary  city 
houses  it  is  only  necessary  to  connect  the  windows  and  doors, 
front  and  back,  of  the  first  two  stories  and  the  opening  in  the 
roof.  The  entire  cost  will  not  generally  exceed  one  hundred 
dollars.  In  the  country  the  cost  would  of  course  be  somewhat 
greater,  in  the  average  house  probably  between  a  hundred  and 
fifty  and  two  hundred  dollars.  The  apparatus  once  in,  the  only 
expense  is  the  maintenance  of  the  battery.  This  will  generally 
be  very  small,  probably  not  more  than  a  dollar  a  year.  Con- 
sidering the  security  gained,  the  outlay  required  is  not  excessive, 
and  builders  find  that  is  fully  made  up  to  them  in  increased  rents. 
It  is  not  improbable  that  the  apparatus  will  eventually  be  con- 
sidered as  necessary  to  the  complete  equipment  of  a  house  as  now 
are  water-  and  gas-pipes. 


The  Steam  Engine^  . 

George  C.  V.  Holmes 

[Holmes's  The  Steam  Engine  is  one  of  a  series  of  Text- 
Books  of  Science  "adapted  for  the  use  of  artisans  and 
students  in  public  and  science  schools."  The  didactic 
purpose  of  the  book  is  apparent  in  the  style  of  the  selec- 
tion reprinted.  The  general  movement  is  from  simple  to 
complex,  with  the  explanation  of  an  easy  laboratory 
experiment  serving  to  make  clear  the  basic  elements  and 

"  From  Chapter  i  (pages  1-14)  of  The  Steam  Engine  (Longmans,  Green 
and  Co,  1902).  Reprinted  by  permission  of  the  publishers.  The  use  of 
the  selection  was  suggested  by  Lamont's  Specimens  of  Exposition  (Holt,  1894). 


TECHNICAL  DESCRIPTION  187 

essential  principles  of  operation  of  the  simple  types  of 
steam  engine  described  later.] 

The  complete  study  of  the  steam  engine  is,  in  its  nature,  some- 
what complex,  involving  as  it  does  an  acquaintance  with  the 
sciences  of  heat,  of  chemistry,  and  of  pure  and  applied  mechanics, 
as  well  as  a  knowledge  of  the  theory  of  mechanism  and  the  strength 
of  materials.  It  is  proposed,  therefore,  to  begin  this  work  vby 
showing,  in  a  very  simple  case,  how  steam  can  be  used  to  do  work, 
and  then  to  proceed  to  describe  an  actual  steam  engine  of  the 
most  modern  construction  but  one  which  at 
the  same  time  is  remarkably  free  from  com- 
plexity. When  studying  this  description,  the 
student  will  soon  find  out  how  it  is  that  the 
perfect  knowledge  of  the  steam  engine  in- 
volves an  acquaintance  with  so  many  branches 
of  science;  and  the  order  in  which  these  sub- 
jects must  be  studied,  so  far  as  they  bear  on 
the  matter  in  hand,  will  naturally  be  suggested 
by  the  description. 

Take  a  hollow  cylinder  (Fig.  i)  of  indefinite 
height,  the  bottom  of  which  is  closed  while  the 
top  remains  open,  and  fill  this  cylinder  to  the       lljiijiili''  ^ 

height  of  a  few  inches  with  water.  Next  cover 
in  the  water  by  means  of  a  flat  plate,  ot  piston, 
which  fits  perfectly  the  interior  of  the  cyUnder, 
and  then  apply  heat  to  the  water;  we  shall  Fig.  i. 

witness  the  following  phenomena.  After  the 
lapse  of  some  minutes  the  water  will  begin  to  boil,  and  steam 
will  accumulate  at  its  upper  surface  between  it  and  the  piston, 
which  latter  will  be  raised  slightly  in  order  to  make  room  for  the 
steam.  As  the  boiling  process  continues,  more  and  more  steam 
will  be  formed,  and  the  piston  will  be  raised  higher  and  higher, 
till  the  whole  of  the  water  is  boiled  away,  and  nothing  but 
steam  is  contained  in  the  cylinder.  Now  this  apparatus,  con- 
sisting of  cylinder,  piston,  water,  and  fire,  is  an  elementary  form 
of  steam  engine  of  the  simplest  kind.  For  a  steam  engine  may 
be  defined  as  an  apparatus  for  doing  work  by  means  of  heat  ap- 
plied to  water;  and  it  is  manifest  that  the  appliance  just  de- 
scribed, inconvenient   and   clumsy  though  it    may  be,   perfectly 


i88    COMPOSITION  OF  TECHNICAL  PAPERS 

answers  to  the  definition;  for  the  piston  is  a  weight,  and  this  weight 
has  been  raised  to  a  certain  height  by  the  formation  of  steam 
from  the  water.  Now  the  raising  of  a  weight  through  a  height  is  a 
particular  form  of  doing  work,  and  consequently  this  combination 
is  an  apparatus  capable  of  doing  work  by  means  of  heat  applied 
to  water. 

If,  instead  of  a  simple  piston,  we  had  taken  one  loaded  with 
weights,  and  applied  heat  as  before,  the  result  would  have  been 
similar  but  not  precisely  the  same.  The  water  would  not  have 
begun  to  boil  so  soon,  and  when  it  was  all  boiled  away  the  loaded 
piston  would  not  have  risen  to  the  same  height  as  did  the  simple 
one.  The  reason  of  this  will  be  amply  explained  in  the  chapters 
on  heat.  Supposing  that,  having  raised  the  weight  to  the  utmost 
height  it  would  go,  we  then*  removed  it  from  the  piston,  and  wished 
to  employ  the  apparatus  in  order  to  raise  a  similar  weight  to  the 
same  height,  we  should  have  to  bring  back  the  steam  to  its  original 
condition  of  water.  This  we  could  do  by  removing  the  fire  and  by 
surrounding  the  cylinder  instead  with  cold  water.  The  result 
would  be  that  the  steam  would  all  condense  into  water,  and  fall 
back  to  its  original  place,  the  piston  following  it,  and  everything 
would  be  ready  for  a  fresh  start.  Now,  though  this  apparatus 
answers  the  definition  of  a  steam  engine,  it  is,  nevertheless,  a  very 
bad  one,  for  the  following  reasons.  The  only  kind  of  work  it  can 
do  is  the  raising  of  weights  through  certain  heights.  "When  we 
want  to  repeat  the  operations  we  have  to  remove  the  fire  and  sur- 
round the  cylinder  with  cold  water,  and  then  replace  the  fire,  which 
is  a  most  cumbrous  process.  While  condensing  the  steam  we  made 
the  cyUnder  cold,  and  a  large  quantity  of  heat  is  wasted  in  warming 
it  again.  Moreover,  when,  at  the  cost  of  a  considerable  amount 
of  fuel,  we  have  heated  the  water  and  turned  it  into  steam,  we 
allow  the  whole  of  the  heat  in  the  steam  to  escape  into  the  cold 
water,  and  thus  become  wasted,  though  it  is  capable  of  doing  much 
more  work  if  properly  used.  Thus  we  see  that  our  elementary 
engine  is  limited  in  its  scope,  clumsy  in  use,  and  extremely  wasteful 
of  fuel.  It  is  in  obviating  these  disadvantages  that  actual  engines 
dififer  from  the  one  we  have  described. 

It  will  have  been  observed  that  this  engine  consists  of  four 
principal  elements,  viz.:  the  fire,  or  source  of  heat;  the  water,  or 
medium  to  which  the  heat  is  applied,  and  by  the  conversion  of 
which  into  steam  the  work  is  done;  the  cylinder  with  movable 


TECHNICAL  DESCRIPTION  189 

piston,  which  contains  the  water  and  steam,  and  which  prevents  the 
latter  from  escaping  into  the  air  when  formed  and  becoming  lost; 
and,  lastly,  the  source  of  cold,  or  the  water  by  means  of  which  the 
steam  was  condensed  and  brought  back  to  its  original  condition. 
The  great  majority  of  actual  engines  consist  of  precisely  the 
same  elements,  more  advantageously  arranged,  with  the  addition  of 
certain  mechanism  for  changing  the  straight  line  movement  of  the 
piston  into  circular,  or  any  other  kind  of  motion.  This  mechanism 
has  also  to  effect  other  subsidiary  objects  which  will  be  fully  de- 
scribed hereafter.  It  should  also  here  be  mentioned  that  if,  instead 
of  condensing  the  steam  by  means  of  cold  water,  we  had  opened  a 
temporary  communication  between  the  steam  space  inside  the 
cylinder  and  the  open  air,  we  should  have  equally  well  succeeded  in 
bringing  the  piston  back  to  its  original  position,  when,  by  introduc- 
ing into  the  cylinder  a  fresh  quantity  of  water,  we  could  have  again 
raised  the  weights. 

In  practice  the  arrangement  adopted  is  as  follows: 

1.  The  source  of  heat,  and  the  vessel  containing  the  water  to 
be  boiled,  are  kept  quite  separate  and  distinct  from  the  cylinder. 
These  parts  of  the  apparatus  are  called  respectively  the  furnace 
and  boiler.  The  steam  is  supplied  from  the  boiler,  where  it  is 
generated,  to  the  cylinder  where  it  is  used,  as  it  is  wanted,  by 
means  of  a  pipe,  called  the  steam  pipe. 

2.  The  steam,  after  doing  its  work  in  the  cylinder,  is  led  away 
through  a  second  pipe,  called  the  exhaust  pipe,  into  the  open 
air,  or  else  to  be  condensed  in  a  separate  vessel  kept  quite  apart 
from  the  cylinder,  and  which  is  called  the  condenser. 

3.  The  cylinder,  instead  of  being  open  at  one  end,  and  of  indefinite 
length,  is  closed  at  both  ends,  and  in  length  seldom  exceeds  twice 
the  diameter  of  the  piston. 

4.  The  steam,  instead  of  being  used  only  on  one  side  of  the 
piston,  is  admitted  alternately  to  and  exhausted  from  each  side  in 
succession,  so  that  when  the  engine  is  in  use,  the  piston  is  constantly 
travelling  backwards  and  forwards  from  one  end  to  the  other  of  the 
cylinder. 

5.  Suitable  openings  are  made  at  each  end  of  the  cylinder  to  allow 
the  steam  alternately  to  enter  and  escape,  and  valves  driven  by 
suitable  mechanism  are  provided  in  order  to  ensure  that  the  admis- 
sion and  escape  of  the  steam  shall  take  place  at  the  proper  moments. 

6.  Instead  of  placing  the  weights  to  be  lifted  directly  upon  the 


1 90    COMPOSITION  OF  TECHNICAL  PAPERS 

piston,  a  cylindrical  bar  or  rod  called  the  piston  rod  is  attached 
firmly  to  the  centre  of  the  piston,  and  is  continued  through  one 
end  of  the  cylinder  to  the  open  air,  so  that  the  outside  end  of  the 
rod  moves  backwards  and  forwards  in  a  straight  line,  exactly  as 
the  piston  does.  By  means  of  a  suitable  mechanism,  which  will  be 
fully  described  hereafter,  this  straight  line  motion  of  the  piston 
rod  end  is  changed  into  rotary  or  circular  motion,  so  that  the 
engine  can  be  used,  not  only  for  lifting  weights  up  in  a  vertical 


Fig.  2. 


Fig.  3. 


direction,  but  for  doing  any  kind  of  work  which  may  be  required 
of  it. 

The  manner  in  which  all  this  may  be  accomplished  in  practice 
will  be  shown  in  the  following  description  and  drawings  of  an  engine 
and  boiler,  which  are  here  selected  for  description  on  account  of 
their  simplicity  of  construction.  We  will  commence  with  the 
source  of  heat,  and  apparatus  for  turning  the  water  into  steam;  then 
go  on  to  the  engine  proper,  i.e.,  the  cylinder  with  the  mechanism 


TECHNICAL  DESCRIPTION  191 

belonging  to  it.  The  abstracter  of  heat,  or  condenser,  will  be  con- 
sidered in  a  separate  chapter.  Fig.  2  is  an  elevation  of  the  boiler, 
Fig.  3  a  vertical  section  through  its  axis,  and  Fig.  4  a  horizontal 
section  through  the  furnace  bars. 

The  type  of  steam  generator  here  exhibited  is  what  is  known  as 
a  vertical  tubular  boiler.  The  outside  casing  or  shell  is  cylindrical 
in  shape,  and  is  composed  of  wrought  iron  or  steel  plates  riveted 
together  as  shown  in  ¥\g.  2.  The  top,  which  is  likewise  composed 
of  the  same  material,  is  slightly  dome-shaped,  except  at  the  centre, 
which  is  cut  away  in  order  to  receive  the  chimney,  a,  which  is 
cylindrical  in  shape  and  formed  of  thin  wrought-iron  plates.  The 
interior  is  shown  in  vertical  section  in  Fig.  3.  It  consists  of  a 
furnace  chamber,  &,  which  contains  the  fire.  The  furnace  is  formed 
like  the  shell  of  the  boiler  of  wrought  iron  or  steel  plates  in  the  form 
of  a  cylinder,  the  top  of  which  is  covered  by  a  — 

flat  circular  plate,  cc,  firmly  attached  to  the  J^^^^-^^^S^ 
cylindrical  portion  by  flanging  and  riveting.  h.j^^^^^^Sc\ 
The  bottom  is  occupied  by  the  grating,  on  |-Y5^^^^=5Yh 
which  rests  the  incandescent  fuel.  The  grat-  H^^  ^ErV 
ing  consists  of  a  number  of  cast-iron  bars,  ^v^S^^^^^^ 
d  (Fig.  3),  and  shown  in  plan  in  Fig.  4,  placed  ^^^"-^-^j^^ 
so  as  to  have  the  interstices   between  them  ^ 

like  the  grate  of  an  ordinary  fireplace.  The 
bottom  of  the  furnace  is  firmly  secured  to  the  outside  shell  of  the 
boiler  in  the  manner  shown  in  Fig.  3.  The  top  covering  plate,  cc, 
is  perforated  with  a  nuinber  of  circular  holes  of  from  one  and  a  half 
to  three  inches  diameter,  according  to  the  size  of  the  boiler.  Into 
each  of  these  holes  is  fixed  a  vertical  tube  made  of  brass,  wrought 
iron,  or  steel,  shown  at  ///  (Fig.  3).  These  tubes  pass  through 
similar  holes,  at  their  top  ends  in  the  plate  gg,  which  latter  is  firmly 
riveted  to  the  outside  shell  of  the  boiler.  The  tubes  are  also 
firmly  attached  to  the  two  plates,  cc,  gg.  They  serve  to  convey 
the  flame,  smoke,  and  hot  air  from  the  fire  to  the  smoke  box,  h, 
and  the  chimney,  a,  and  at  the  same  time  their  sides  provide  ample 
heating  surface  to  allow  the  heat  contained  in  the  products  of  com- 
bustion to  escape  into  the  water.  The  fresh  fuel  is  thrown  on 
to  the  grating  when  required  through  the  fire  door,  A  (Fig.  2). 
The  ashes,  cinders,  etc.,  fall  between  the  fire  bars  into  the  ash  pit, 
B  (Fig.  3).  The  water  is  contained  in  the  space  between  the  shell 
of  the  boiler,  the  furnace  chamber,  and  the  tubes.     It  is  kept  at  or 


192    COMPOSITION  OF  TECHNICAL  PAPERS 

about  the  level,  ww  (Fig.  3),  the  space  above  this  part  being  re- 
served for  the  steam  as  it  rises.  The  heat,  of  course,  escapes  into 
the  water,  through  the  sides  and  top  plate  of  the  furnace,  and 
through  the  sides  of  the  tubes.  The  steam  which,  as  it  rises  from 
the  boiling  water,  ascends  into  the  space  above  ww,  is  thence  led 
away  by  the  steam  pipe  to  the  engine.  Unless  consumed  quickly 
enough  by  the  engine,  the  steam  would  accumulate  too  much  within 
the  boiler,  and  its  pressure  would  rise  to  a  dangerous  point.  To 
provide  against  this  contingency,  the  steam  is  enabled  to  escape 
when  it  rises  above  a  certain  pressure  through  the  safety  valve, 
which  is  shown  in  sketch  on  the  top  of  the  boiler  in  Fig.  2.  The 
details  of  the  construction  of  safety  valves  will  be  found  fully 


Fig.  s. 


described  in  Chapter  IX,  which  is  devoted  exclusively  to  the 
consideration  of  boilers  and  their  fittings.  In  the  same  chapter 
will  be  found  full  descriptions  of  the  various  fittings  and  acces- 
sories of  boilers,  which  it  would  be  out  of  place  here  to  describe 
in  detail,  such  as  the  water  and  pressure  gauges,  the  apparatus  for 
feeding  the  boiler  with  water,  for  producing  the  requisite  draught 
of  air  to  maintain  the  combustion,  and  also  the  particulars  of  the 
construction  of  the  boilers  themselves  and  their  furnaces,  and  the 
principles  on  which  their  strength  is  determined,  and  their  various 
parts  proportioned,  so  as  to  fully  realise  the  effects  intended. 


TECHNICAL  DESCRIPTION 


193 


We  now  come  to  the  description  of  the  engine,  and  the  type 
selected  for  illustration  is  that  usually  called  horizontal  single 
cylinder,  direct  acting. 


Fig.  6. 


Fig.  5  is  an  elevation  of  the  exterior.  Fig.  6  is  a  horizontal 
section  of  the  cylinder,  piston,  and  valve  box.  Fig.  7  is  a  plan. 
The  cylinder  is  shown  at  A,  Figs.  5,  6,  7;  its  construction  is  best 
seen  from  the  section,  Fig.  6.    It  is  formed  of  cast  iron,  the  ends 


Fig.  7. 


being  flanged  to  allow  of  the  cylinder  cover  or  end  plate,  aa,  and 
the  frame,  PP,  being  bolted  to  it.  The  piston  is  shown  at  B\ 
it  is  a  circular  cast-iron  disc,  made  to  fit  the  cylinder  in  a  steam- 


194    COMPOSITION  OF  TECHNICAL  PAPERS 

tight  manner.  Into  the  piston  is  fixed  the  piston  rod,  C,  which 
passes  through  the  front  cylinder  cover,  the  place  where  it  passes 
through  being  made  steam-tight  by  the  stuffing  box,  D.  The 
front  end  of  the  piston  rod  is  fastened  to  the  crosshead,  E  (Fig.  5), 
which  is  a  joint  used  for  connecting  the  piston  rod  to  the  connecting 
rod,  F,  in  such  a  manner  as  to  allow  the  latter  to  swing  in  a  vertical 
plane  as  the  piston  travels  backwards  and  forwards.  The  cross- 
head  is  also  provided  with  two  slides,  ee  (Fig.  5),  which  move  be- 
tween the  guide  bars,  Jf  (Figs.  5  and  6),  and  which  prevent  the 
piston  rod  from  being  bent,  and  from  moving  otherwise  than  in  a 
straight  line.  The  connecting  rod,  F  (Figs.  5  and  7),  joins  the  end 
of  the  piston  rod  to  the  crank  pin,  G.  The  crank  axle  in  which  the 
crank  is  formed  is  shown  in  section  at  H  (Fig.  5),  but  is  seen  more 
clearly  in  the  plan,  Fig.  7,  where  it  is  shown  passing  through  the 
two  bearings,  LL.  The  distance  between  the  centre  of  the  crank 
pin,  G,  and  the  centre  of  the  crank  axle,  H  (Fig.  5),  is  called  the 
length  of  the  crank  arm,  and  is  exactly  equal  to  half  the  distance 
which  the  piston  moves  from  one  end  to  the  other  of  the  cylinder. 
Supposing  now  that  steam  were  allowed  to  flow  from  the  boiler 
into  the  cylinder  in  such  a  manner  as  to  obtain  admission  behind 
the  piston,  B\  this  latter  would  commence  to  travel  towards  the 
front  cover  of  the  cylinder,  and  in  doing  so  would  push  forward 
the  piston  rod  and  the  crosshead.  The  end  of  the  connecting  rod 
next  the  crosshead  would  also  be  pushed  forward,  but  the  other  end 
of  the  connecting  rod  which  encircles  the  crank  pin,  not  being 
free  to  move  simply  forward,  would  describe  an  arc  of  a  circle 
round  the  centre  of  the  crank  axle,  H,  and  in  so  doing  the  direction 
of  the  rod  would  become  inclined  so  as  to  form  an  angle  with  the 
axis  of  the  cylinder.  By  the  time  the  piston  has  travelled  to  the 
front  end  of  the  cylinder,  the  crank  pin  will  have  been  turned  round 
into  the  position  G'  (Fig.  5),  diametrically  opposite  to  its  initial 
position.  Suppose  that,  just  before  this  takes  place,  the  steam  is 
shut  off  from  the  back  of  the  piston,  and  the  steam  already  in  the 
cylinder  is  allowed  to  escape,  while  at  the  same  time  fresh  steam 
from  the  boiler  is  allowed  to  enter  the  cylinder  at  the  front  side  of 
the  piston,  this  latter  will  commence  to  travel  back  to  its  original 
position,^  and  in  doing  so  will  cause  the  crank  pin  to  revolve  from 
the  position  G'  (Fig.  5),  through  a  semi-circle,  till  it  reaches  its 

iPor  the  sake  of  simplifying  the  description,  no  account  is  here  taken  of 
the  action  at  the  dead  centres.     See  p.  197.     [Author's  note.] 


TECHNICAL  DESCRIPTION 


195 


original  position,  it  having  thus  described  a  complete  revolution 
round  the  centre  of  the  crank  axle,  while  the  piston  was  making  a 
double  stroke  backwatds  and  forwards.  This  operation  may  be 
repeated  as  often  as  we  like  provided  we  have  a  suitable  apparatus 
for  admitting  the  steam  alternately  on  each  side  of  the  piston,  and 
then  allowing  it  to  escape  either  into  the  open  air  or  a  condenser. 
The  manner  in  which  the  steam  admission  is  regulated  is  as 
follows.  By  referring  to  the  section  (I""ig.  6),  it  will  be  seen  that 
a  box-like  casing,  MM,  is  cast  in  one  piece  with  the  cylinder  and  on 
one  side  of  it.  This  box  contains  the  valve,  F,  which  controls  the 
flow  of  the  steam.  It  will  be  noticed  that  the  side  of  the  cylinder 
next  the  valve  box  contains  two  passages,  ss'\  these  are  called  the 
steam  ports  because  the  steam  by  means  of  them  gains  access 
to  and  escapes  from  either  end  of  the  cylinder.  For  the  sake  of 
clearness  the  following  diagram,   Fig.   8,  is   given,   showing  the 


Fig.  8. 


valve  and  side  of  a  cylinder  to  a  larger  scale.  The  cast-iron  box 
containing  the  valve  is  always  filled,  when  the  engine  is  at  work, 
with  steam  from  the  boiler.  If  the  valve  occupies  the  position 
shown  in  Fig.  8,  the  steam  can  not  enter  the  cylinder  at  all,  because 
both  ports  are  covered  up  by  the  valve.  If  the  latter,  however, 
be  moved  a  little  to  the  right  so  as  to  uncover  the  steam  port  s,  two 
things  will  happen.  The  steam  will  be  enabled  to  pass  through  the 
port  5  into  the  cylinder,  and  push  the  piston  forward  from  left  to 
right,  while  at  the  same  time  the  port  s'  will  be  uncovered  by  the 
inner  edge  of  the  valve,  and  any  steam  which  may  be  contained  in 
the  cylinder  on  the  right-hand  side  of  the  piston  will  be  enabled  to 


1 96    COMPOSITION  OF  TECH  NIC  A  L  PA  PERS 

escape  through  the  port  s'  into  the  interior  hollow  of  the  valve,  and 
thence  into  the  exhaust  passage  e,  whence  it  can  escape  to  the 
air  of  the  condenser.     This  condition  of  things  is  shown  by  Fig.  q. 

If  when  the  piston  has  reached  the  end  of  its  forward  stroke 
the  valve  be  moved  backwards  into  the  corresponding  position  on 
the  other  side,  the  steam  port  s'  will  then  be  uncovered  and  will 
allow  the  boiler  steam  to  enter  the  cylinder,  and  force  the  piston 
back  from  right  to  left,  while  the  steam  on  the  left-hand  side  of 
the  piston  will  be  enabled  to  escape  into  the  exhaust  passage. 

The  foregoing  remarks  must  be  looked  upon  as  merely  an  ele- 
mentary sketch  of  the  working  of  this  particular  sort  of  valve 
(which  is  commonly  called  the  D  slide  valve).  The  proper  way  of 
proportioning  the  parts  of  the  valve,  the  widths  of  the  steam 


Fig.  9- 


IX)rts,  and  the  methods  of  driving  the  valve  so  as  to  admit  and  cut 
off  the  fresh  steam  and  release  the  exhaust  steam  precisely  at  the 
right  moments  during  the  stroke  of  the  piston,  are  points  of  the 
greatest  nicety  and  require  the  most  careful  study,  and  are  fully 
described  in  Chapter  VII;  but  enough  has  been  now  said  to  illus- 
trate the  method  of  working  in  a  general  way  without  going  into 
complexities. 

It  will  be  noticed  that  the  valve  is  connected  by  a  rod  (see  Fig. 
7)  with  a  cam,  C,  fixed  to  the  crank  axle  of  the  engine.  This  cam, 
which  is  called  an  eccentric,  drives  the  valve  backwards  and 
forwards;  its  manner  of  working  will  be  found  described  in  the 
chapter  already  referred  to. 

When  the  centre  of  the  crank-pin  occupies  either  the  point  C, 


'    TECHNICAL  DESCRIPTION  197 

Fig.  5,  or  the  diametrically  opposite  position,  the  centre  line  of  the 
crank  is  in  the  prolongation  of  the  axis  of  the  cyUnder  and  connect- 
ing rod,  and  it  is  evident  that  when  in  either  of  these  positions, 
which  are  called  the  dead  centres,  the  steam  would  only  tend  to 
press  the  crank  axle  against  its  bearings,  LL,  Fig.  7,  and  would 
exercise  no  rotating  effect  whatever.  Consequently  unless  some 
means  can  be  devised  for  getting  the  crank  over  the  dead  centres 
the  engine  will  stick  fast. 

The  plan  invariably  adopted  with  a  single  cylinder  engine  is 
to  provide  a  heavy  fly-wheel,  shown  in  elevation  in  Fig.  5,  and  in 
plan  in  Fig.  7.  The  momentum  acquired  by  this  fly-wheel  during 
the  stroke  carries  the  crank  over  the  dead  centre.  In  addition  to  the 
above  the  fly-wheel  exercises  other  useful  functions  which  are 
explained  in  Chapter  V,  but  which  need  not  be  dwelt  upon  at 
present. 

The  engine  which  has  been  described  above  is  mounted  on  the 
heavy  combined  bed  plate  and  frame  PPP,  shown  in  elevation  Fig. 
5,  and  in  plan  Fig.  7.  The  bed  plate  is  bolted  down  to  a  solid 
mass  of  masonry  as  shown  in  Fig.  5. 

For  our  present  purposes  it  is  not  necessary  to  examine  into  the 
other  details  of  the  mechanism,  such  as  the  governor  and  feed 
pump  shown  on  Fig.  7. 


13 


CHAPTER  VII 
EXPOSITION  OF  PROCESSES 

Principles 

Technical  description,  it  was  shown  in  the  preceding 
chapter,  is  governed  partly  by  the  principles  of  ordinary 
description;  it  is,  however,  expository  and  riot  descriptive 
in  aim.  The  exposition  of  a  process  has,  similarly,  some 
kinship  with  narration,  since  it  deals  with  events  in  a 
sequential  relationship;  its  aim  is,  however,  distinctly  ex- 
pository and  not  narrative.  The  mind  of  the  reader  of 
a  process-expositon  strives  to  secure  a  clear  understand- 
ing of  the  stages  of  the  process  and  of  their  relationship 
one  to  another;  this  effort  is  intellectual  and  not  emotional 
as  it  would  be  in  the  case  of  narrative.  The  exposition 
of  a  process  differs  from  a  technical  description  in  the 
material  dealt  with.  Technical  description  deals  with 
concrete  objects,  which  can  be  seen  and  touched;  exposi- 
tion of  a  process  deals  with  the  steps  or  stages  in  a 
process.  Technical  description  is,  in  a  sense,  static; 
process-exposition  is  dynamic, — it  advances  from  one 
point  to  another  until  the  logical  termination  of  the  ad- 
vance has  been  reached. 

The  writer  of  a  process-exposition  is  faced  by  two 
questions, — first.  What  shall  I  include?  and  second, 
What  shall  the  arrangement  be?  In  process-expositions 
which  are  simple  neither  problem  is  very  difficult  of  solu- 
tion; in  more  complex  explanations  the  second,  espe- 
cially, may  offer  some  difficulties. 

198 


EXPOSITION  OF  PROCESSES  199 

The  question  of  what  to  include  in  the  exposition  of  a 
process  is  related  to  the  question  of  how  detailed  to  make 
the  exposition.  The  subject  itself  imposes  certain  gen- 
eral restrictions,  but  the  writer  may  still  be  puzzled  as 
to  the  fullness  of  treatment.  This  he  will  find  to  depend 
very  largely  upon  his  purpose.  If  the  process  is  very 
complex,  and  it  is  his  aim  to  give  the  reader  merely  a 
general  idea  of  it,  his  explanation  will  necessarily  be 
little  more  than  an  outline.  If,  on  the  other  hand,  he 
aims  to  give  the  reader  an  understanding  of  the  details 
of  the  process,  his  exposition  will,  of  course,  be  longer 
and  more  complex.  The  fullness  of  treatment  is  a  mat- 
ter which  he  must  determine  independently  for  each 
process-exposition.  He  should,  it  ought  to  be  added,  be 
especially  careful  in  all  cases  to  develop  his. subject  evenly. 
This  means  that  one  process-detail  should  be  given  the 
same  completeness  of  development  as  another  process- 
detail  of  equal  importance;  if  this  is  not  done,  the  exposi- 
tion will  be  out  of  proportion  and  will  give  a  false 
impression. 

The  problem  of  arranging  the  material  of  a  process-  . 
exposition  is  simpler  than  that  of  any  other  expository 
type.  In  general,  the  organization  is  chronological,  and 
the  planning  is  to  be  done  by  stages  or  steps  in  the  pro- 
cess. In  the  explanation  of  simple  processes  in  which  the 
various  stages  are  unchanging  in  method  and  in  sequence 
the  parts  of  the  exposition  should  come  in  a  simple 
straight  line;  the  explanation  of  the  steps  should  be 
merely  enumerative  and  sequential.  Where,  however, 
the  process  is  complex,  and  two  or  more  alternative  meth- 
ods must  be  presented,  or  where,  as  is  often  the  case,  two 
or  more  steps  in  the  process  go  on  simultaneously,  it  is 
necessary   for   the   writer   to   carry   one   process-detail 


200    COMPOSITION  OF  TECHNICAL  PAPERS 

through  and  then  return  for  the  alternative  or  simulta- 
neous detail.  This  practice  is  exactly  like  that  of  the 
novelist  who,  after  dealing  with  one  group  of  charactei-s 
in  his  story,  leaves  them  to  turn  to  the  adventures  of 
another  group,  which  have  occurred  "in  the  meantime." 
These  problems  of  arrangement  may  perhaps  be  made 
clearer  by  a  series  of  diagrams: 

I.  Exposition  of  simple  process. 
Intro.    I    Stage  i    |    Stage  2    |    Stage  3    |    Stage  4    |    etc. 

II.  Exposition  of  process  with  alternative  process-details.    . 
Stage  3  (Practice  A) 
Intro.  I  Stage  i  |  Stage  2  |  y/  \    |  Stage  4  |  etc. 

\Stage  3  (Practice  B)/ 

///.  Exposition  of  processwith  process-details  occurring  simultaneously. 

Stage  3 
Intro.    I  Stage  i   |    Stage  2    |  /Stage  4\   |  Stage  6    |  etc. 

\Stagej/ 

Process-expositions  of  Type  I  present  little  difficulty. 
With  Types  II  and  III  comes  the  question.  Which  of  the 
alternative  or  simultaneous  details  shall  be  taken  up 
first?  In  the  case  of  two  or  more  alternative  practices 
it  is  usually  best  to  explain  first  that  one  which  is  the 
most  generally  employed,  or  that  one  which  offers  the 
best  building  ground  for  the  others.  This  last  means 
that  two  alternative  process-details  are  rarely  so  entirely 
different  that  an  explanation  of  one  may  not  be  used  as 
a  part  explanation  of  the  other.  After  completing  the 
first  explanation,  the  writer  may  usually  say,  "The  alter- 
native practice  differs  from  the  one  just  explained  only 
in  the  following  details,"  and  then  proceed  to  give  only 
the  points  of  difference.     It  is  good  compositional  econ- 


EXPOSITION  OF  PROCESSES  201 

omy,  therefore,  to  explain  first  the  practice  which  ofifers 
the  best  basis  upon  which  to  build  subsequent  explana- 
tions. In  the  case  of  details  occurring  simultaneously 
the  plan  must  be  determined  by  the  nature  of  the  case. 
It  is  usually  best  here  to  take  up  first  the  most  basic 
process  or  the  one  which  links  most  closely  with  the  pre- 
ceding stage,  and  then  to  build  the  others  upon  this.  In 
some  cases  the  arrangement  is  of  little  importance  so 
long  as  the  explanation  of  each  process-detail  is  clear. 

It  should  be  noted  that  in  all  these  types  the  matter 
of  clear  and  careful  transition  is  of  great  importance. 
The  reader  should  be  told  when  a  new  step  in  the  process 
is  entered  upon,  and  alternative  and  simultaneous  pro- 
cess-details should  always  be  carefully  marked  off  from 
preceding  stages.  If  this  is  not  done,  the  reader  may 
confuse  one  stage  with  another.  Confusion  may  also 
result  from  the  writer's  carelessness  in  alluding  in  his 
explanation  of  one  process-stage  to  details  which  he  has 
not  yet  explained,  or  from  his  use  of  terms  which  he  has 
not  defined.  He  should  remember  the  situation  of  the 
reader.  The  writer  has  in  mind  all  of  the  steps  in  the 
process;  the  reader  knows  only  those  which  have  been 
explained  up  to  the  point  reached  in  his  reading.  It  is, 
accordingly,  quite  legitimate  for  the  writer  to  build  his 
new  explanation  upon  details  which  he  has  already  cov- 
ered, as  a  child  will  build  a  pier  into  the  water  stone  after 
stone;  it  is,  on  the  other  hand,  quite  wrong  for  him  to 
depend  upon  the  reader's  understanding  of  things  not 
yet  explained.  Sometimes  it  seems  necessary  to  do  this; 
where  it  must  be  done,  the  gap  should  be  filled  in  with 
some  such  phrase  as,  "The  specific  function  of  this  part 
of  the  machine  will  appear  later" — a  promissory  note 
for  what  is  to  come. 


202    COMPOSITION  OF  TECHNICAL  PAPERS 

There  remain  to  be  considered  the  introduction  of  the 
process-exposition,  and  the  relation  of  the  descriptive  and 
the  process  elements. 

The  introduction  of  a  process-exposition  usually  de- 
mands some  special  attention.  It  is  seldom  well  to  begin 
bluntly  with  an  explanation  of  the  first  stage  of  the  pro- 
cess; it  is  usually  much  better  to  give  first  some  statement 
of  the  general  direction  of  the  whole  process,  with  a  defi- 
nition and  an  indication  of  the  object  of  the  process  and 
its  underlying  principles.  This  serves  the  same  purpose 
in  a  process-exposition  that  a  general  introductory  de- 
scription of  the  whole  does  in  a  technical  description;  it 
provides,  that  is,  a  basic  conception  which  assists  the 
reader  to  a  ready  understanding  of  the  relationship  of 
each  stage  of  the  process  to  the  process  as  a  whole.  A 
brief  historical  account  of  the  evolution  of  the  process 
may  often  be  used  effectively  to  give  a  better  under- 
standing of  the  reason  for  some  of  the  process-details. 
The  introductory  elements  mentioned  are  not,  of  course, 
of  service  in  all  process-expositions;  it  is  for  the  writer  to 
determine  in  each  case  whether  or  not  they  will  be  of 
value  to  the  reader.  In  any  case  the  introduction  should 
not  be  over-long  in  proportion  to  the  whole  composition ; 
and  it  should  contain  only  material  which  will  be  of 
actual  service. 

It  is  obvious  that  in  all  explanations  of  manufacturing 
processes,  descriptions  of  the. plant  and  of  the  apparatus 
employed  are  likely  to  figure,  and  it  is  sometimes  puzzling 
to  know  just  how  to  combine  these  descriptive  elements 
with  the  process  elements.  A  mistake  frequently  made 
is  that  of  giving  all  the  descriptions  first  under  the  as- 
sumption that  the  reader  can  carry  them  in  his  mind 
while  reading   the  explanations   of   the  process-details 


EXPOSITION  OF  PROCESSES  203 

which  follow.  Excepting  in  very  short  explanations  this 
cannot  be  done.  It  is  much  the  best  plan  to  give  at 
the  beginning  only  a  general  outline  description  of  the 
whole  plant  in  connection  with  the  outline  exposition  of 
the  process,  very  much  as  the  apparatus  employed  in  a 
laboratory  experiment  will  be  briefly  described  at  the 
beginning  of  a  report  on  the  experiment.  Aside  from 
this  introductory  general  description  all  descriptive  ele- 
ments should  be  scattered  through  the  exposition,  being 
combined  with  the  explanations  of  the  process-details 
with  which  they  belong.  If  this  is  done,  there  will  be 
no  improper  dislocation  of  elements  that  really  belong 
together.  Illustrations,  sketches,  and  diagrams  should 
be  employed  to  make  these  descriptions  clearer,  wherever 
such  auxiliary  devices  will  be  serviceable.  Various  tricks 
may  be  used  to  indicate  movements  of  parts,  such  as 
arrows  and  dotted  lines,  and  the  dimensions  not  shown 
in  a  plane  figure  may  be  indicated  by  perspective  and 
skeleton  drawings  aild  by  reference  to  parts  lying  in  a 
direction  "away  from  the  reader."  But  as  these  tricks 
belong  more  properly  to  the  science  of  the  draftsman, 
they  need  not  be  taken  up  in  detail  here. 


204    COMPOSITION  OF  TECHNICAL  PAPERS 


STUDENT  THEMES 

[These  themes  are  for  class  analysis.  They  are  not 
designed  to  serve  as  models.] 

I.  How  Photographs  are  Made 

In  making  a  photograph  it  is  first  necessary  to  have  a  camera  and 
a  sensitive  plate.  The  camera  is  a  light-proof  box,  which  has  a  lens 
inserted  in  one  end.  The  lens  is  covered  by  a  shutter  which 
excludes  all  light  from  the  box  excepting  when  an  exposure  is 
.  being  made.  The  sensitive  plate  is  a  glass  oblong  which  is  coated 
with  certain  chemicals  which  are  dififerently  affected  by  various 
intensities  of  light.  This  plate  is  held  in  the  end  of  the  camera 
opposite  that  which  contains  the  lens. 

The  camera  can  be  carried  to  any  desired  place,  the  shutter 
opened  for  an  instant,  and  "the  picture  is  taken."  Light,  re- 
flected from  the  object  being  photographed,  enters  the  box 
through  the  lens,  is  focused  on  the  plate,  and  causes  certain 
chemical  changes  on  the  surface  of  the  plate,  which  make  possible 
the  following  operation  called  developing.  In  a  room  illuminated 
only  by  red  or  dim  yellow  light,  the  plate  is  removed  from  the 
camera  and  placed  in  the  developing  solution.  An  image  begins 
to  form  on  the  plate,  which  has,  until  this  time,  remained  perfectly 
clear.  The  change  goes  on  until  all  lines  and  figures  are  sharply 
defined.  Then  the  plate  is  removed  from  the  bath  and  is  placed 
in  the  fixing  bath. 

The  fixing  bath  removes  all  material  from  the  plate  which  was 
not  acted  upon  by  the  light  and  consequently  not  affected  by  the 
developer.     The  plate  is  then  washed  and  set  aside  to  dry. 

We  now  have  what  is  termed  a  negative.  All  parts  of  the  object 
pictured  which  were  white  will  appear  black,  and  all  black  objects 
will  appear  white.  The  negative  may  be  retouched  to  correct  flaws 
or  to  remove  harsh  lines,  or  pictures  may  be  printed  without  this 
extra  work. 


EXPOSITION  OF  PROCESSES  205 

Printing  consists  in  making  positive  pictures  from  the  com- 
pleted negative.  In  doing  this  the  same  dark  room  is  used  as  be- 
fore. The  negative  is  placed  in  a  frame,  and  a  piece  of  sensitized 
paper  is  held  firmly  against  its  face.  The  frame  is  then  placed  in 
some  bright  light  for  a  short  time  and  returned  to  the  dark  room 
to  be  finished.  Some  papers  require  development  much  the  same 
as  a  plate,  while  others  need  merely  to  be  made  permanent  by  im- 
mersion in  one  bath.  Both  varieties  must  be  thoroughly  washed 
and  dried  before  they  are  finished. 

When  expensive  work  is  being  done,  the  prints  are  closely  in- 
spected, and  all  defects  due  to  poor  work  or  defective  material 
are  then  obliterated  with  a  small  brush  and  dark  oil  paint. 

2.  Leveling 

The  object  of  leveling,  or,  as  it  is  often  called,  running  levels,  is 
to  find  the  actual  or  relative  elevation  of  a  point  or  a  series  of  points 
on  the  land.  The  method  employed  in  this  work  is  getting  the 
elevation  of  the  level  instrument  used  by  sighting  on  a  rod  held  on 
a  known  elevation,  and  finding  the  elevation  of  a  point  ahead  by 
sighting  on  the  rod  held  on  that  point. 

There  are  two  different  kinds  of  instruments  useci  in  this  work, 
namely,  the  mounted  level  and  the  hand  level.  The  hand  level  is 
used  only  for  special  work  where  accuracy  is  not  a  necessity,  and 
it  will  therefore  not  be  considered  in  this  article.  The  mounted 
level  consists  essentially  of  a  very  finely  made  telescope  about 
sixteen  inches  in  length,  which  is  mounted  on  three  wooden  legs 
known  as  the  tripod  of  the  instrument.  The  construction  of  the 
telescope  to  the  tripod  is  such  as  to  allow  free  horizontal  revolu- 
tion of  the  telescope  about  an  axis  perpendicular  to  its  own  axis, 
and  to  permit  vertical  movement  of  the  telescope  by  means  of  ad- 
justing screws.  The  general  outline  of  the  level  may  be  obtained 
from  the  sketch. 

In  one  of  the  lenses  of  the  telescope  are  cross-wires  placed  at 
right  angles  to  each  other.  One  of  the  wires  is  truly  vertical,  and 
the  other  is  truly  horizontal.  On  the  bottom  of  the  telescope  and 
rigidly  attached  to  it  is  a  spirit  level.  The  object  of  this  is  to  enable 
the  levelman  to  keep  the  telescope  truly  horizontal  at  times  when 
he  is  reading  levels. 


2o6    COMPOSITION  OF  TECHNICAL  PAPERS 

In  running  levels  the  elevation  of  the  starting  point  must  be 
known,  or  else  an  assumed  elevation  may  be  used.  The  order  of 
procedure  is  as  follows.  The  instrument  is  set  up  at  a  distance 
of  about  three  hundred  feet  from  the  starting  point  so  that  the 
spirit  level  shows  the  telescope  to  be  truly  horizontal  as  it  revolves 
about  the  vertical  axis.  This  condition  is  accomplished  by  means 
of  the  slow  motion  screws  (see  sketch).  The  levelman  now  sights 
through  the  telescope  on  a  rod  which  is  graduated  into  feet  and 
tenths  of  a  foot  and  sometimes  into  thousandths  of  a  foot,  and 
which  is  held  on  the  starting  point.  He  reads  the  distance  on  the 
rod  above  the  original  point  which  coincides  with  the  horizontal 
cross-wire  in  the  telescope.  This  distance  which  he  reads  will  give 
the  elevation  of  the  telescope  when  it  is  added  to  the  elevation  of 
the  original  point.     Now  the  man  with  the  graduated  rod,  generally 


- rgig  scope- ^ 

.  "A  r~,~.  ~     ~~~~~~P  eyepiete 

nne  of  sirtHt  -* 


spir-rt  tevgl  ■  ^ 


?     I?     I  "tP*^ Siov'^  motion  screws. 

'II    in.  I  "  -* 


called  the  rodman,  moves  forward  ahead  of  the  instrument  a  dis- 
tance approximately  equal  to  the  space  between  the  first  point  and 
the  instrument. 

The  rodman  selects  a  point  easily  seen  by  the  levelman  and  sets 
his  rod  up  in  a  vertical  position.  The  levelman  now  sights  through 
the  telescope  again  and  reads  the  distance  that  coincides  with  the 
horizontal  cross-wire.  This  distance,  subtracted  from  the  eleva- 
tion of  the  telscope  as  previously  determined,  will  give  the  elevation 
of  the  point  over  which  the  rod  is  held.  The  levelman  takes  up  his 
instrument  at  this  stage  and  sets  up  ahead  of  the  rodman  and 
repeats  the  program  as  explained  above. 

The  foregoing  is  the  general  procedure  when  running  levels. 


EXPOSITION  OF  PROCESSES  207 

The  distance  between  the  points  the  elevations  of  which  are  to 
be  determined  may  be  any  distance,  since,  as  explained  above,  the 
elevation  of  the  telescope  and  the  last  point  is  always  known, 
and  the  elevation  of  any  point  ahead  may  be  obtained  by  taking  a 
reading  of  the  rod  on  that  point,  or,  if  the  point  is  too  far  ahead, 
intermediate  set-ups  will  be  necessary. 


3.  Charging  an  Iron  Foundry  Cupola 

An  ordinary  iron  foundry  cupola  is  about  five  feet  in  diameter 
at  the  base  and  is  approximately  forty  high,  the  upper  fifteen  feet 
being  cone  shaped  with  a  top  diameter  of  about  two  feet. 

The  foundation,  or  part  upon  which  the  cupola  proper  rests,  is 
made  of  iron  and  resembles  an  ordinary  round  topped  table  with 
four  legs.  The  top  of  the  foundation,  which  is  the  bottom  of  the 
cupola,  differs  from  the  top  of  an  ordinary  table  in  that  it  has  a 
central  two  foot  circular  doorway  into  which  a  flanged  door  fits. 
The  door  is  supported  by  heavy  hinges  and  opens  downward  with 
the  flange  on  the  under  side  so  that  when  the  door  is  closed  and 
locked,  the  flange  will  strike  the  bottom  of  the  cupola  proper. 

The  outside  of  the  cupola  is  made  of  sheet  steel,  and  it  is  lined 
inside  with  a  double  wall  of  fire  brick  to  a  height  of  about  twenty- 
five  feet  or  up  to  where  the  cone  shaped  top  begins.  The  charge 
doorway,  or  opening  for  putting  in  the  charge,  is  about  twenty  feet 
above  the  bottom  of  the  cupola  and  about  two  feet  above  a  second 
floor  called  the  charge  floor  of  the  foundry,  while  on  the  first  floor  a 
trough  to  convey  the  molten  iron  away  from  the  cupola  is  attached 
to  it  just  below  a  small  tap  hole,  which  is  about  four  inches  above  the 
bottom  of  the  cupola.  This  part  or  side  of  the  structure  is  called 
the  front,  and  that  part  diametrically  opposite  is  called  the  back. 
In  the  back  of  the  cupola  and  about  two  feet  above  its  bottom,  is 
a  hole  through  which  an  air  pipe  enters,  and  thus  by  forcing  an  air 
blast  through  this  pipe,  the  cupola  is  furnished  with  a  good 
draught. 

In  order  to  charge  the  cupola  a  good  coke  fire  is  built  on  the  top 
of  the  table,  or  foundation,  after  which  an  amount  of  iron  called  a 
charge  is  placed  on  the  coke  through  the  charge  doorway  on  the 
second  floor.  More  coke  is  then  thrown  on  the  iron,  after  which 
more  iron  is  thrown  on  this  coke;  thus  the  process  continues,  the 


2o8   COMPOSITION  OF  TECHNICAL  PAPERS 

charges  consisting  of  alternate  layers  of  coke  and  iron.  When  the 
furnace  is  filled  to  within  a  few  feet  of  the  charge  door,  the  air  blast 
is  turned  on,  and  as  soon  as  the  iron  begins  to  melt,  the  tap  hole  is 
plugged  with  a  ball  of  moist  clay.  After  sufficient  time  to  melt 
the  lower  charge  of  iron  has  elapsed,  the  clay  is  removed  from  the  tap 
hole,  and  the  iron  is  drawn  off  and  poured  into  molds.  When  the 
lower  charge  has  melted  and  has  been  drawn  off,  the  tap  hole  is 
again  plugged  with  clay.  The  contents  of  the  cupola  drop  to  the 
bottom,  and  the  next  charge  begins  to  melt.  It  is  then  drawn  off 
in  a  similar  manner  to  that  just  described.  Thus  the  process  con- 
tinues until  all  of  the  iron  has  been  melted,  after  which  the  cupola 
is  cleaned  and  recharged. 

4.  The  Making  of  Pig  Iron 

Pig  iron  is  made  by  reducing  its  ores  with  carbon  at  high  tem- 
peratures. The  ores,  which  consist  of  the  oxides,  are  reduced 
in  blast  furnaces.  These  furnaces  are  cylindrical  in  shape  and 
are  from  eighty  to  one  hundred  feet  high  and  about  twenty  feet  in 
diameter.  They  consist  of  a  tube  of  iron  or  steel,  which  is  lined 
with  fire  brick  which  has  openings  at  the  lower  end.  These  open- 
ings are  connected  with  tubes  or  tuyeres  to  air  blowers  by  means 
of  which  hot  air  can  be  forced  through  the  furnace.  To  start  the 
furnace,  it  is  necessary  to  build  a  fire  of  coke  in  the  bottom.  The 
air  is  then  turned  on  and  the  furnace  charged  from  the  top  through 
a  bell  and  hopper  arrangement  which  prevents  the  gases  and  heat 
from  escaping  while  the  furnace  is  thus  being  charged.  The 
charge  consists  of  iron  ore  properly  mixed  with  coke  and  limestone. 
The  purpose  of  the  limestone  is  to  form  slag  with  the  impurities  in 
the  ore.  No  matter  what  the  material  added  to  the  ore  to  produce 
the  fusible  slag,  it  is  termed  the  flux.  The  charge  is  carried  to  the 
top  of  the  furnace  by  some  form  of  mechanical  conveyor  and  then 
introduced  into  the  furnace.  As  the  air,  which  has  previously  been 
heated  to  about  800  degrees,  is  blown  through  the  furnace,  the 
charge  becomes  very  hot.  Carbon  dioxide  forms  in  the  lower  part 
of  the  furnace  as  a  result  of  the  burning  of  the  coke.  As  the  carbon 
dioxide  passes  through  the  hot  layers  of  coke,  it  is  reduced  to  carbon 
monoxide,  which  acts  on  the  iron  ores,  reducing  them  to  iron.  The 
gases  formed  are  still  rich  in  carbon  monoxide,  so  they  are  passed 


EXPOSITION  OF  PROCESSES  209 

through  pipes  and  used  as  fuel  to  heat  the  air  blown  into  the  furnace. 
Part  of  these  gases  are  also  used  to  run  gas  engines.  The  slag  and 
iron  settle  to  the  lower  part  of  the  furnace  in  two  layers,  the  heavier 
iron  going  to  the  bottom.  The  slag  and  iron  may  then  be  drawn 
ofiF  through  tap  holes.  The  molten  iron  is  then  poured  into  molds 
of  sand  and  allowed  to  cool.  These  bars  are  known  as  pig  iron,  and 
are  further  dealt  with  to  form  steels  and  cast  iron.  The  slag  of  the 
furnace  is  used  in  making  Portland  cement.  The  process  can  be 
made  continuous  if,  as  the  iron  and  slag  are  drawn  ofif,  fresh  charges 
of  fuel,  ore,  and  flux  are  added. 


5.  The  Manufacture  of  a  Mercury  in  Glass  Thermometer 

In  the  manufacture  of  a  mercury  in  glass  thermometer  the 
principal  operations  are  cleaning,  filling,  and  graduating  the  glass 
thermometer  tube.  A  small  glass  tube,  like  any  ordinary  ther- 
mometer tube  with  the  end  opposite  the  bulb  broken  ofif,  is  taken. 
This  tube  must  first  be  thoroughly  cleaned  with  some  cleansing 
solution  such  as  strong  nitric  acid.  The  bulb  of  the  tube  is  heated, 
and  then  the  open  end  is  put  beneath  the  surface  of  a  mass  of 
nitric  acid.  As  the  bulb  cools,  the  nitric  acid  is  drawn  into  the 
tube  and  bulb.  When  the  tube  has  been  filled,  it  is  placed  in  a 
bath  of  boiling  nitric  acid  and  left  there  for  several  hours,  or  until 
the  workman  is  positive  that  the  tube  is  absolutely  clean.  Then 
it  is  taken  from  the  bath  and  repeatedly  heated  and  cooled  until 
the  last  traces  of  the  acid  have  disappeared.  The  tube  is  then 
ready  to  be  filled  with  mercury. 

To  fill  the  tube  with  mercury  the  workman  proceeds  in  the  same 
way  as  he  did  when  he  filled  the  tube  with  acid,  except  that  he 
must  be  more  careful  to  get  all  air  bubbles  out  of  the  tube.  He  fills 
the  tube  up  to  a  desired  level  at  a  given  temperature.  This  level 
is  arbitrarily  set  by  the  workman,  who  knows  at  what  range  of 
temperature  the  thermometer  is  to  be  used.  Having  filled  the  tube 
to  the  desired  height,  he  holds  it  in  a  vertical  position  and  heats 
the  bulb  until  the  mercury  has  expanded  enough  to  fill  the  tube 
nearly  to  the  top.  He  then  heats  the  open  end  of  the  tube  until 
the  glass  melts  and  seals  the  opening.  The  thermometer  is  now 
ready  to  be  graduated. 

To  graduate  the  thermometer  one  must  have  at  least  two  fixed 


2IO    COMPOSITION  OF  TECHNICAL  PAPERS 

points  on  it  and  must  know  the  number  of  divisions  between  these 
points.  The  Fahrenheit  scale  thermometer  has  two  fixed  points, — 
namely,  thirty-two  degrees,  the  point  at  which  ice  melts,  and 
two  hundred  and  twelve  degrees,  the  point  at  which  water  boils 
under  atmospheric  pressure.  The  distance  between  the  two  points 
is  divided  into  one  hundred  and  eighty  equal  parts,  called  degrees. 

To  find  the  point  at  which  ice  melts,  the  workman  immerses 
the  thermometer  in  a  mass  of  melting  ice  and  water.  After  the 
mercury  column  has  ceased  to  contract,  the  point  which  the  top  of 
the  column  has  reached  is  marked  on  the  glass  tube.  This  point  is 
at  thirty-two  degrees  Fahrenheit,  according  to  Fahrenheit's 
arbitrary  scale. 

Next,  the  workman  finds  the  point  at  which  water  boils  under 
atmospheric  pressure.  To  do  this  he  places  the  thermometer  bulb 
and  most  of  the  tube  in  a  container  filled  with  water  vapor  (steam) 
coming  directly  from  a  bath  of  boiling  water.  After  the  mercury 
column  has  ceased  to  expand,  he  marks  the  point  to  which  the  top  of 
the  column  has  risen.  This  point  is  at  two  hundred  and  twelve 
degrees  Fahrenheit.  The  distance  between  these  two  points  is  now 
divided  into  one  hundred  and  eighty  equal  parts  called  degrees. 
The  workman  now  etches  the  divisions  and  the  numbers  correspond- 
ing to  each  tenth  division,  such  as  o°,  10°,  20°,  etc.,  in  the  glass. 
The  thermometer  is  now  complete,  and  is  ready  to  use  as  a  tempera- 
ture measuring  device  for  temperature  between  thirty-two  degrees 
and  two  hundred  and  twleve  degrees.  Its  accuracy  depends,  of 
course,  on  the  care  taken  by  the  workman. 

6.  The  Laying  of  Underground  Concrete  Conduits^ 

Underground  ducts  are  coming  into  greater  and  greater  use  in 
cities  as  a  means  of  ridding  the  streets  of  all  manner  of  electric 
wires  and  poles.  Numerous  kinds  of  ducts  are  being  used,  but  it 
is  the  purpose  of  this  article  to  describe  the  all-concrete  ducts,  and 
to  explain  the  method  of  laying  them. 

Besides  the  concrete  used,  which  is  mixed  at  the  scene  of  opera- 
tions, other  articles  must  be  used  in  the  laying  of  these  ducts. 
Wooden  molds,  and  chairs,  weights,  and  slabs  of  concrete  must  be 
provided.     The  chairs  are  castings  of  cemept  and  sand  concrete 

1  The  original  outline  of  this  theme  is  printed  on  page  36. 


EXPOSITION  OF  PROCESSES 


211 


of  about  the  form  and  dimensions  shown  in  Fig.  i.  The  figure 
shows  one  used  in  laying  ducts  four  in  a  layer.  Three  or  six  duct 
chairs  may  also  be  used.  These  chairs  are  used  merely  to  support 
the  molds  in  position  until  the  concrete  sets.  However,  they  remain 
in  position  after  the  molds  have  been  drawn  as  part  of  the  system  of 
ducts,  so  they  must  be  supplied  in  numbers  proportioned  to  the 
extent  of  the  work  in  hand.  The  wooden  molds  are  rods  of  Georgia 
pine  about  six  feet  long,  and  of  a  U-shaped  cross-section  that  will 


Fig.  I. 


fit  exactly  one  of  the  slots  in  the  chair  (Jlf ,  Fig.  i).  These  molds  are 
kept  oiled  to  prevent  the  concrete  from  sticking  to  them.  The 
weights  are  merely  fifty-pound  concrete  blocks,  about  eighteen 
inches  long,  and  provided  with  an  iron  handle  to  facilitate  handling 
(see  Wt  Fig.  3).  The  slabs  used  are,  like  the  chairs,  of  cement  and 
sand  concrete,  eighteen  inches  square  and  one  inch  thick.  They 
too  must  be  provided  in  considerable  numbers,  as  they  are  in- 
corporated into  the  duct  system. 


^m.. 


Fig.  2. 


In  laying  the  ducts,  the  first  step  is  the  excavation.  A  ditch 
some  eighteen  inches  wide  and  from  three  to  four  feet  deep  is  dug 
by  the  usual  methods.  Next,  a  layer  of  cement,  sand,  and  crushed 
stone  concrete  is  poured  into  the  trench  to  the  depth  of  two  inches 
and  carefully  leveled  and  tamped.  This  is  merely  for  foundation. 
When  the  concrete  has  set  enough,  in  from  ten  to  eighteen  hours, 
chairs  are  placed  transversely  in  the  trench  at  regular  six  foot 
intervals.  Molds  are  placed  in  the  slots  so  that  the  arrangement  is 
somewhat  as  shown  in  a  side  view,  Fig.  2,  CC  being  the  chairs,  and 


212    COMPOSITION  OF  TECHNICAL  PAPERS 


MM,  the  molds.  Weights,  W,  Fig.  3,  are  then  put  on  at  each  chair 
to  hold  the  molds  down  when  the  concrete  is  poured.  Concrete 
used  for  the  body  of  the  ducts  is  made  of  cement,  sand,  and  fine 
gravel.  This  concrete  is  poured 
rather  thin  and  is  allowed  to  fill 
completely  the  space  under,  around, 
and  between  the  molds,  up  flush 
with  the  top,  and  over  the  sides  of 
the  trench.  After  the  cement  has 
set  for  about  six  hours,  the  weights 
are  taken  off,  and  the  molds  drawn. 
The  slabs  are  then  laid  across  the 
tops  of  the  ridges  between  the  ducts, 
one  at  a  time.  As  each  slab  is  laid, 
the  crack  between  it  and  the  next  preceding  one  is  carefully  pointed 
with  cement.    To  make  sure  that  the  ducts  are  clear  after  the  slabs 


^l^^^y 


Fig.  3- 


StKCtt  Sur-fi. 


ace 


f. 


i 


pirt  Fifh'nj 


I 


wpypy^^^' 


Fig.  4. 


are  in  position,  wooden  plugs  that  fit  the  ducts  are  drawn  through 
them,  the  length  of  one  slab  at  a  time,  as  the  work  progresses.  On 
the  smooth  surface  presented  by  the  top  of  the  slabs,  other  layers  of 


EXPOSITION  OF  PROCESSES  213 

ducts  may  be  laid  until  the  necessary  number  is  reached.  On  top 
of  the  last  layer  another  two-inch  layer  of  cement,  sand,  and  crushed 
stone  concrete  is  added.  When  this  sets,  dirt  filling  is  tamped  in, 
and  the  surface  of  the  street  restored.  A  transverse  section  of  a 
completed  eight  duct  trench  is  shown  in  Fig.  4.  These  kinds  of 
ducts  are  built  only  in  straight,  level  runs,  from  manhole  to  manhole. 
The  concrete  ducts  are  much  less  expensive  than  tile  or  fibre 
ducts,  unless  the  cost  of  labor  is  abnormally  high.  It  is  claimed 
too  that  they  form  a  more  rigid  system  when  in  the  ground,  being 
practically  monolithic;  but  this  claim  is  doubtful  as  other  ducts  are 
usually  set  in  concrete.  However,  where  it  is  inexpedient  to  have 
too  much  street  open  at  one  time,  concrete  ducts  must  be  ruled  out. 
The  time  it  takes  for  the  successive  layers  to  set  would  make  progress 
extremely  slow  unless  long  runs  were  laid  at  one  time. 

7.  Electroplating  Non-metallic  Objects 

The  electroplating  of  non- metallic  objects,  or  the  process  of 
metallization,  as  it  is  often  called,  provides  a  fairly  simple  means 
of  accurately  preserving  the  orginal  form  of  flower,  insect,  or  other 
non-metallic  object  to  which  it  is  applied.  The  process  might  be 
termed  a  sort  of  three-dimensional  photography,  for  the  reproduc- 
tion includes  all  of  the  details  that  would  show  in  a  photograph, 
and  in  addition  possesses  the  advantages  of  form  and  depth. 
Photography  is  sometimes  called  scientific  painting;  the  metalliza- 
tion process  may  just  as  correctly  be  termed  scientific  sculpture. 

The  essential  steps  in  the  process  may  be  enumerated  as  follows: 
First,  the  selection  and  preliminary  preparation  of  the  specimen; 
second,  forming  upon  the  surface  of  the  object  an  electrically 
conductive  film  of  sulphide  of  silver;  third,  electroplating  with 
copper  this  conductive  film  of  sulphide  of  silver;  fourth,  removing 
from  the  copper  shell  thus  formed  the  organic  matter  of  the  original 
object;  fifth,  cleaning  the  copper  reproduction  and  giving  it  a 
pleasing  appearance. 

Considerable  care  must  be  exercised  in  selecting  the  specimen, 
for  not  all  kinds  of  specimens  lend  themselves  well  to  this  treat- 
ment. The  specimen  should  possess  two  main  qualifications: 
first,  it  should  be  fairly  firm,  in  order  that  it  will  hold  its  shape  dur- 
ing treatment;  second,  inasmuch  as  recesses  are  hard  to  electro- 
14 


214   COMPOSITION  OF  TECHNICAL  PAPERS 

plate,  it  should  be  reasonably  free  from  such  defects.  In  the  case 
of  a  flower  it  is  always  best  to  select  a  bud  that  is  just"  opening 
out,  and  to  remove  any  loose  petals.  The  successful  plating  of  a 
full-blown  rose  is  possible,  with  a  great  deal  of  care  and  patience; 
but  such  success  is  extremely  doubtful.  Insects,  such  as  flies, 
beetles,  dragon-flies,  etc.,  which  do  not  possess  too  many  hairs, 
lend  themselves  well  to  the  process;  but  fur-bearing  animals,  or 
such  insects  as  moths,  butterflies,  etc.,  which  have  a  fine  bloom 
on  their  wings,  should  not  be  attempted. 

Having  selected  the  specimen,  one  should  next  attach  to  it  a 
fine  copper  wire,  which  will  provide  electrical  contact  for  the  elec- 
troplating process  later  on.  For  the  purpose  of  covering  the  sur- 
face of  the  object  with  an  electrically  conductive  layer  of  silver 
sulphide,  one  needs  a  solution  of  silver  nitrate,  containing  about 
one  ounce  of  the  salt  to  the  half  pint.  The  silver  nitrate  should 
first  be  dissolved  in  as  little  water  as  possible,  and  the  rest  of  the 
solution  then  made  up  with  grain  alcohol.  The  specimen  is  dipped 
in  this  solution  and  then  hung  in  a  chamber  where  the  fumes  of 
hydrogen  sulphide  gas,  made  by  the  action  of  dilute  sulphuric  acid 
on  ferrous  sulphide,  can  act  upon  the  silver  nitrate  and  thus  change 
it  to  the  black,  metallic  looking  silver  sulphide.  The  specimen  is 
then  hung  up  to  dry,  which  should  take  about  a  half  hour. 

For  electroplating  on  top  of  the  silver  sulphide  film,  the  regular 
sulphate  of  copper  plating  bath  is  used.  This  bath  is  made  up  by 
dissolving  enough  copper  sulphate  in  water  to  make  the  hydro- 
meter reading  about  i6  degrees  Beaume,  and  then  by  adding  enough 
sulphuric  acid  to  bring  up  the  hydrometer  reading  about  two  de- 
grees more.  The  specimen  is  hung  in  this  bath  as  cathode,  with 
plates  of  copper  as  anodes,  and  the  current  is  turned  on.  If  prop- 
erly prepared,  the  specimen  will  slowly  become  covered  with 
metallic  copper.  The  covering  starts  next  to  the  copper  wire 
which  holds  the  specimen  and  spreads  slowly  out  over  the  rest  of 
the  surface.  The  amount  of  current  which  is  flowing  through  the 
solution  should  be  regulated  carefully  so  as  not  to  obtain  a  brittle 
deposit. 

After  the  deposit  has  become  fairly  heavy,  which  should  be  after 
from  two  to  three  hours,  the  specimen  is  taken  out,  thoroughly 
soaked  in  water,  to  remove  the  plating  solution,  and  then  heated 
to  a  red  heat  in  order  to  carbonize  the  organic  matter  inside,  and 
to  anneal  the  copper  and  make  it  less  brittle.     The  carbon  may  be 


EXPOSITION  OF  PROCESSES  215 

broken  up  by  inserting  a  wire  through  a  small  opening  in  the  copper 
shell,  and  should  then  be  shaken  out. 

The  surface  of  the  copper  may  be  cleaned  by  being  dipped  in 
nitric  acid.  It  may  then  be  further  electroplated  with  silver,  gold, 
or  any  desired  metal,  and  should  be  lacquered  to  preserve  this  finish. 


2i6    COMPOSITION  OF  TECHNICAL  PAPERS 

EXPOSITIONS  OF  PROCESSES 

Suggestions  on  the  Study  of  Mathematics^ 

[The  following  little  article  was  included  in  the  chapter 
on  process-exposition  because  the  main  part  of  it  con- 
tains suggestions  for  the  successful  carrying  out  of  an 
intellectual  process,  the  solution  of  a  mathematical  prob- 
lem, and  it  is  expected  to  furnish  "priming"  for  a  theme 
on  My  Method  of  Working  a  Problem,  How  to  Prepare  a 
Laboratory  Report,  or  some  similar  subject  which  requires 
a  basic  chronological  plan.  On  the  rhetorical  side  the 
little  exposition  may  be  studied  for  its  division  and  ar- 
rangement of  material.  It  should  be  compared  with 
Student  Theme  No.  5  of  Chapter  VIII  (p.  272),  which,  it 
will  be  observed,  is  not  an  exposition  of  a  process.] 

It  is  obviously  impracticable  to  lay  down  specific  directions  that 
will  adequately  guide  the  student  in  the  study  of  any  science;  never- 
theless, it  is  hoped  that  the  following  general  suggestions  may  be  of 
service,  and  assist  the  student  early  in  his  course  to  acquire  habits 
of  work  essential  to  success  in  the  study  of  mathematics  and  of  the 
other  exact  sciences. 

Successful  intellectual  work  depends  very  largely  upon  the  power 
of  concentration.  Fortunately  this  power  can  be  acquired  and  culti- 
vated. The  student  must  study  away  from  interruption  and  then 
must  not  permit  his  work  to  become  interrupted  by  himself  or  by 
others.  By  holding  his  attention  upon  his  work  and  by  keeping 
his  mind  from  wandering  to  extraneous  matters,  the  student  will 
cultivate  a  fundamental  habit  that  will  tend  to  assure  his  success 
both  in  and  out  of  college. 

In  a  course  in  mathematics  a  student  (i)  studies  a  textbook  and 

1  Issued  to  students  by  the  Department  of  Mathematics,  University  of 
Wisconsin.  Reprinted  by  permission  of  Professor  Charles  S.  Slichter,  Chair- 
man of  the  Department. 


EXPOSITION  OF  PROCESSES  217 

(2)  works  exercises  and  problems.  An  assignment  for  a  given  day- 
may  therefore  consist  of  the  study  of  mathematical  principles  and 
theory  (such  as  theorems,  definitions,  and  explanations  of  pro- 
cesses) or  it  may  consist  of  the  working  out  of  exercises  and  problems, 
or,  as  is  usually  the  case,  it  may  consist  of  the  theory  and  principles 
of  processes,  together  with  an  assignment  of  exercises  illustrative 
of  the  theory. 

I.  The  Study  of  the  Textbook 

Studying  a  mathematical  textbook  involves  much  more  than  the 
mere  reading  of  the  statements  of  principles  and  of  the  explanation 
of  processes.  The  student  must  usually  read  the  assigned  para- 
graphs several  times  and  must  frequently  turn  back  and  re-read 
portions  of  the  text  included  in  previous  lessons.  In  this  manner 
the  various  points  in  the  reasoning  or  explanations  can  be  thought 
over,  and  the  habit  of  asking  self-put  questions  about  the  work  can  be 
acquired.  This  habit  is  what  constitutes  "the  scientific  method  of 
study."  It  is  the  proper  method  in  all  departments  of  pure  and 
technical  science. 

First  of  all,  in  preparing  a  lesson,  try  to  find  out  what  it  is 
about — what  its  purpose  is.  Try  to  decide  how  you  yourself 
would  go  about  the  accomplishment  of  the  task  and,  if  possible, 
make  an  independent  attempt  of  your  own.  The  more  consideration 
you  give  to  such  an  attempt,  the  greater  scientific  power  you  will 
gain. 

In  particular: 

(A)  The  student  should  remember  that  the  words  in  science  have 
exact  meanings  and,  of  course,  these  meanings  must  be  known  to  the 
student.  In  studying  mathematics  the  student  should  acquire 
and  use  the  language  of  mathematics.  For  example,  he  should  not 
say  "equation"  when  he  means  "expression."  Indeed,  he  should 
go  farther  than  this.  He  should  make  a  conscious  effort  to  use 
absolutely  correct  English,  not  only  in  written  work  but  in  oral 
work  as  well. 

(B)  While  studying  the  text,  work  out  theorems  or  illustrative 
examples  with  pen  and  ink.  Do  not  rely  upon  a  mere  reading — 
even  repeated  readings — of  a  new  piece  of  reasoning  or  of  the 
explanation  of  a  new  process. 

(C)  Read  over  all  of  the  lesson  assigned  in  the  text  a  last  time  after 


2 1 8    COMPOSITION  OF  TECHNICAL  PAPERS 

working  the  assigned  exercises.  The  text  will  probably  have  a  new 
meaning  after  working  out  the  special  cases  in  the  exercises.  This 
habit  will  give  a  meaning  to  the  words,  "Learn  by  doing." 

(D)  Finally,  make  a  mental  summary  of  each  lesson. 

(E)  Review  often. 


2.  The  Working  of  Exercises 

(F)  Read  each  exercise  or  problem  carefully  and  plan  a  method 
of  attack  in  advance  in  order  to  facilitate  arrangements  of  equations 
and  computations  and  the  drawing  of  figures. 

(G)  Look  at  your  result  and  see  if  it  is  a  reasonable  one. 
(H)  Check  result. 

(I)  Indicate  the  results  by  a  distinguishing  mark  or  summarize 
in  logical  order. 

(J)  The  figures  and  diagrams  should  have  sufficient  lettering, 
titles,  etc.,  to  make  them  self-explanatory.  The  units  of  measure 
used  should,  of  course,  be  clearly  indicated. 

(K)  Do  all  work  neatly  the  first  time  and  (except  drawings) 
invariably  in  ink.  Try  to  have  the  first  draft  sufficiently  neat  in 
appearance  and  arrangement  to  hand  in  to  your  instructor. 

(L)  After  the  first  draft  has  been  finished,  read  it  over  carefully 
to  see  where  it  may  be  improved  in  method  or  arrangement  and 
think  about  the  processes  you  have  used.  If  small  changes  only  are 
needed  to  effect  the  desired  improvement,  make  them  by  drawing 
lines  through  the  portions  to  be  changed  and  by  making  neat 
insertions.     If  considerable  changes  are  necessary,  do  the  work  over. 

The  study  and  improvement  of  the  work  will  prove  to  be  of  fully 
as  much  importance  to  you  as  the  doing  of  the  work  itself. 

(M)  See  to  it  that  each  piece  of  work  or  exercise  is  complete. 
On  any  piece  of  written  work  the  nature  of  the  problem  should  be 
clearly  and  briefly  stated.  The  student  should  learn  to  think  of 
each  piece  of  work  as  a  thing  that  is  in  itself  worth  while.  Hence 
each  detail  should  be  attended  to  before  the  work  is  submitted  to 
the  instructor.  See  that  sufficient  explanation  is  given  and  that  the 
numbers  and  magnitudes  are  adequately  named  and  labelled. 

(N)  Hand  in  work  at  the  time  it  is  due. 


EXPOSITION  OF  PROCESSES  219 

3.  Orderliness,  System,  Neatness,  and  the  Rating  or 
Marking  of  Work 

The  student  may  come  to  the  University  with  the  notion  that  the 
only  thing  desirable  in  mathematics  is  accuracy  of  numerical  re- 
sults. To  correct  such  a  notion  and  to  offer  every  possible  induce- 
ment toward  neatness  and  attractiveness  of  work : 

(O)  The  department  offers  a  maximum  of  eighty-five  points  out 
of  the  possible  one  hundred  on  the  basis  of  excellence  of  method  and 
accuracy  of  result.  The  remaining  fifteen  are  given  on  the  basis 
of  neatness,  accuracy  of  spelling,  choice  of  English,  and  general 
appearance  of  the  work.  The  instructor  reserves  the  right  to  re- 
fuse to  consider  any  piece  of  work  that  is  not  attractive  in 
appearance. 

4.  Specific  Directions 

The  formal  or  merely  mechanical  requirements  of  good  scien- 
tific work  are  important — in  fact,  the  importance  of  these  require- 
ments can  hardly  be  overemphasized,  on  account  of  the  very 
general  neglect  of  them  in  the  early  training  of  many  of  the  students 
entering  American  colleges  and  universities. 

The  instruments  and  materials  needed  for  mathematical  work 
are  outlined  in  the  introduction  to  Elementary  Mathematical 
Analysis  (pp.  xi,  xii)  and  need  not  be  repeated  here. 

(P)  All  mathematical  work  should  be  done  on  one  side  of  stand- 
ard size  letter  paper,  S}^^  X  n  inches.  This  is  the  smallest  sheet 
that  permits  of  proper  arrangement  of  mathematical  work.  The 
paper  should  be  punched  for  preservation  in  notebook  cover.  The 
left  side  of  the  top  of  each  sheet  should  bear  a  description  of  the 
work,  or  references  to  the  pages  of  the  text,  and  the  right  side  of  the 
top  of  each  sheet  should  bear  the  student's  name.  A  special  form 
of  paper  pad  has  been  prepared  for  general  mathematical  work. 
It  is  known  as  "Calculation  sheet.  Form  M2,"  and  it  should  in 
general  be  used. 

(Q)  Have  assigned  exercises  in  readiness  (in  folder)  to  hand  in 
to  instructor  every  day. 

(R)  Keep  in  a  loose  leaf  notebook  or  in  a  folder  all  exercises 
returned  by  your  instructor  and  all  other  exercises  solved,  in 
order  that  you  may  have  them  for  review  and  may  be  able  to  show 
them  at  the  end  of  the  semester  if  they  are  called  for. 


2  20    COMPOSITION  OF  TECHNICAL  PAPERS 

(S)  Full  credit  will  not  be  given  for  work  that  is  handed  in  later 
than  the  day  on  which  it  is  due. 

5.  Corrections 

The  student  should  keep  these  suggestions  for  reference.  Re- 
marks concerning  the  student's  written  work  will  often  be  made 
by  reference  to  the  lettered  paragraphs  of  this  leaflet;  thus  if  a 
piece  of  work  bears  the  letter  (G)  it  means  that  the  result  is  an 
unreasonable  one;  (M)  means  that  the  nature  of  the  problem  is 
not  stated,  or  that  sufl&cient  explanation  is  not  given,  or  that  num- 
bers and  magnitudes  are  not  adequately  named  and  labelled,  etc. 

Erecting  a  Tent^ 

Herbert  M.  Wilson 

Geographer,  United  States  Geological  Survey 

[Not  all  process-expositions  deal  with  manufacturing 
processes.  Many  are  explanations  of  abstract  processes, 
like  the  exposition  of  a  method  of  solving  a  problem  in 
mathematics,  and  many  explain  how  things  are  accom- 
plished, rather  than  made.  To  this  last  class  belongs 
the  following  simple  explanation  of  how  a  tent  should 
be  erected,  ditched,  and  floored.  Such  explanations 
quite  frequently  take  the  form  of  directions,  which  differ 
from  simple  explanations  only  in  the  more  direct  attitude 
of  instruction  which  characterizes  them,  with  the  impera- 
tive mode  of  the  verb  replacing  the  indicative  and  the 
entire  tone  becoming  definitely  didactic] 

361.  Erecting  the  Tent. — To  properly  set  up  a  tent  it  should 
be  taken  by  the  ridge  and  dragged  away  until  laid  out  flat.  The 
ridge-poles  should  be  inserted  through  the  ventilation-holes,  the 
supporting  poles  inserted  in  the  ridge-pole,  and  the  whole  raised  and 

1  Pages  825-827  of  Topographic  Surveying  (John  Wiley  and  Sons,  1902). 
Reprinted  by  permission  of  the  author  and  the  publishers. 


EXPOSITION  OF  PROCESSES 


221 


the  corners  at  once  guyed  out.  The  corner  ropes  by  which  the 
tent  is  first  stretched  should  be  drawn  in  a  diagonal  direction  so  as 
to  make  an  angle  of  about  45**  with  the  walls.  The  door  should 
be  tied  up  so  that  the  tent  may  be  given  its  proper  shape,  and  the 
wall-corner  loops  pegged  down  and  door  fastened  to  hold  the  whole 
in  place.  Then  the  side  ropes  should  be  guyed  out  and  the  tent 
stretched  taut  by  tightening  a  little  on  each  rope  at  a  time. 

The  fly  must  be  laid  over  the  tent  when  on  the  ground,  and  be 
raised  with  it.  Then  it  must  be  so  stretched  as  to  touch  the  tent 
at  no  point  excepting  at  the  ridge,  while  at  the  eaves  it  should  be 
from  6  to  10  inches  above  the  roof  of  the  tent.  (Fig.  187.)  This 
result  can  be  obtained  by  several  methods.  One  is  to  use  pegs 
with  two  notches,  on  the  lower  of  which  the  tent-guys  are  fastened, 
and  on  the  upper  the  fly-guys;  or  an  additional  row  of  pegs  may  be 
set  a  foot  beyond  the  tent-pegs  for  the  support  of  the  fly-guys. 
Where  much  rain  or  heat  is  encountered,  short 
crotched  poles  about  10  inches  longer  than  the 
height  of  the  wall  should  be  cut  and  one  of  these 
be  set  under  each  of  the  corner  fly-guys  to  raise 
the  fly  away  from  the  tent  roof.  As  a  protec- 
tion in  high  winds  long  guys  should  be  stretched 
from  each  end  of  the  ridge-pole  in  front  and 
rear;  otherwise  storms  blowing  end  on  may  carry 
the  tent  away. 

362.  Tent  Ditching  and  Flooring. — Where 
the  ground  is  moist  or  rains  are  to  be  provided 
against,  the  tent  must  be  ditched  in  order  that 
the  water  shall  not  run  under  it  and  wet  the  soil 
inside  the  tent;  and  where  the  camp  is  to  remain  in  the  same  place 
for  some  time,  the  comfort  of  the  party  will  be  greatly  increased  by 
adding  a  floor  to  the  tent.  To  ditch  a  tent  a  sharp  spade  or  mattock 
should  be  used,  and  the  soil  be  cut  squarely  or  vertically  just  out- 
side the  foot  of  the  wall  (Fig.  192).  The  soil  should  be  pitched 
away  and  an  easy  slope  left  on  the  outside  of  the  spade-cut.  Dirt 
should  never  be  banked  up  against  the  outer  wall  of  the  tent,  as 
it  rapidly  rots  and  destroys  the  canvas.  The  ditch  should  be  cut 
sufficiently  deep  to  assure  its  carrying  off  any  ordinary  rainfall,  and 
should  be  made  deep  or  shallow  in  various  parts  according  to  the 
slope  of  the  ground,  so  that  its  bottom  may  have  a  uniform  slope 
towards  the  lowest  ground.     At  such  point  the  ditch  should  be 


Fig.     192. — Sod- 
cloth  and  Ditch. 


2 2  2  COMPOSITION  OF  TECHNICAL  PAPERS 

carried  away  from  the  tent  a  short  distance  in  order  to  assure  egress 
of  the  water  from  the  ditch. 

The  comfort  of  the  occupants  of  the  tent  is  increased  by  using  a 
small  strip  of  canvas  or  similar  material  as  a  floor  on  which  to  stand 
in  dressing.  Still  better  is  a  canvas  floor  of  the  full  size  of  the  in- 
terior of  the  tent,  and  this  can  rest  upon  the  sod-cloth  to  keep  out 
the  wind.  Where  facilities  for  transportation  permit,  a  wooden 
floor  of  tongue-and-grooved  planks  the  length  of  the  tent — say  9 
feet — and  fastened  together  by  cleats  in  sections  of  3  feet  width 
may  be  provided.  These  3  X  9-foot  sectional  floors  can  be  easily 
handled  in  moving,  and  the  whole  tent  can  be  floored  with  them  or 
only  one  or  more  sections  be  placed  in  the  space  between  two  cots. 

A  still  more  substantial  floor  for  a  permanent  winter  camp  consists 
in  laying  2X4  scantling  as  floor-joists  and  planking  these  over  so  as 
to  make  a  full  floor  which  shall  extend  outside  the  canvas  walls. 
The  rain  will  run  under  this,  and  a  little  carpet  or  canvas  on  it  will 
keep  the  wind  out.  At  each  corner  a  2  X  4  joist  should  be  erected 
the  height  of  the  wall  and  these  corner  posts  should  be  connected 
by  smaller  scantling  so  as  to  form  a  railing  the  height  of  the  wall. 
Over  this  the  tent  will  be  stretched,  the  framing  of  scantling  holding 
it  out  in  shape.  It  is  unnecessary  except  in  very  high  winds  to 
guy  out  tents  stretched  in  this  manner,  the  guys  to  the  fly  being 
sufficient  protection. 

Submarine  Construction^ 

Charles  W.  Domville-Fife 

[A  series  of  simple  explanations  of  different  processes 
employed  in  submarine  construction  of  various  types. 
In  a  study  of  the  article  the  following  should  be  noted: 
(i)  the  introductory  indication  of  the  place  of  the  chap- 
ter in  the  plan  of  the  book,  (2)  the  undertone  of  big  ac- 
complishment and  the  suggestion  by  the  frequent  use  of 
"we"  of  a  "personally  conducted"  explanation,  which 

1  Chapter  XIII  of  Submarine  Engineering  of  To-day  (J.  B.  Lippincott 
Company,  Philadelphia,  and  Seeley,  Service  and  Co.,  Ltd.,  London,  1914). 
Reprinted  by  permission  of  the  J.  B.  Lippincott  Company. 


EXPOSITION  OF  PROCESSES  223 

flavor  the  exposition  to  the  taste  of  the  general  reader, 
(3)  the  employment  of  frequent  simple  analogies,  and  (4) 
the  use  of  diagrams  to  assist  in  the  explanation.  An 
illustration  showing  the  interior  of  an  air-lock  diving  bell 
has  been  omitted  in  reprinting.] 

The  work  of  the  submarine  engineer  may  be  divided  into  three 
sections,  each  of  which  is  really  a  science  in  itself  and  has  its 
own  professors  or  specialists.  The  first  is  covered  by  the  word 
"salvage,"  which  has  already  been  dealt  with;  the  second  is  "con- 
struction," the  subject  of  this  and  the  succeeding  chapter;  and  the 
third  section  is  "demolition,"  which  will  be  dealt  with  later. 
There  are,  of  course,  numberless  other  "jobs"  which  the  submarine 
engineer  and  his  right-hand  man,  the  diver,  are  called  upon  to  do, 
such  as  the  work  performed  on  shipboard  and  in  wells  and  mines, 
but  these  may  be  reckoned  as  subsidiary  to  the  three  great  divisions 
of  the  submarine  branch  of  engineering  science.  During  recent 
years,  however,  a  fourth,  and  even  more  important  branch,  has 
been  added  to  the  already  heavy  and  difficult  task  of  the  engineer; 
this  is  submarine  boat  construction,  about  which,  however,  more 
anon. 

Before  going  further,  let  us  pause  for  a  moment  to  consider 
the  vast  amount  of  submarine  construction  now  undertaken,  and  its 
diverse  character.  Foremost  comes  the  building  of  harbours,  docks, 
and  breakwaters;  stupendous  works  which  the  organised  effort  and 
skill  of  several  thousand  men  can  seldom  erect  within  two  or  three 
years.  The  Libau  Harbour  works  (Port  Alexander  III),  Russia, 
affords  a  brilliant  example  of  the  gigantic  nature  of  such  works. 
The  main  pier  of  this  harbour  is  a  mile  and  a  quarter  in  length,  and 
its  breadth  is  36  feet  at  the  bottom  and  24  feet  at  the  top.  It  is 
constructed  throughout  of  concrete  blocks,  weighing  from  25  to  30 
tons;  and  the  depth  of  water  at  the  pier-head  exceeds  35  feet. 
The  protecting  breakwater,  which  is  three  and  a  half  miles  in  length, 
has  six  heads,  making  three  harbour  entrances,  and  each  head  is 
composed  of  300  concrete  blocks.  These  works  enclose  five  square 
miles  of  water,  and  in  the  pier  itself  there  are  no  less  than  15,753 
immense  blocks  of  concrete.  All  this  is,  of  course,  in  addition 
to  the  temporary  staging  and  piers  required  for  the  purposes  of 
construction. 

One  British  diver,  Mr.  James  Murphy,  and  an  assistant,  sent 


2  24    COMPOSITION  OF  TECHNICAL  PAPERS 

out  by  Messrs.  Siebe,  Gorman  and  Co.,  trained  for  under-water 
work  thirty-seven  Russian  masons,  and,  notwithstanding  the 
rigorous  winter  climate,  the  whole  of  this  gigantic  work  was  com- 
pleted in  three  years  and  nine  months. 

In  order  to  realise  the  number  of  these  huge  harbours,  and  the 
almost  incessant  demand  for  the  extension  and  improvement  of  the 
shipping  accommodation  afforded,  we  have  only  to  consider  for  a 
moment  the  ocean-girt  British  Empire,  with  its  almost  countless 
ports  of  call  in  all  quarters  of  the  globe,  and  the  thousands  of  miles 
of  harbour-dotted  coastline  of  the  two  Americas,  to  arrive  at  a 


Fig.  29. — Plymouth  Sound.     Showing  the  system  of  protecting  a  deep  water 
inlet  by  a  detached  breakwater.     A  natural  harbour  of  the  first  class. 


full  understanding  of  the  vital  importance  to  the  community  of 
this  branch  of  submarine  engineering. 

The  form  in  which  a  harbour  is  constructed  depends  so  much 
upon  the  configuration  of  the  coast,  the  tides,  and  prevailing 
winds,  as  well  as  the  purposes  for  which  it  was  intended  (naval, 
mercantile,  or  fishing),  that  no  general  rules  can  possibly  be  laid 
down.  A  natural  harbour,  that  is  to  say  a  sheet  of  deep  water, 
well-sheltered  by  surrounding  land  and  unaffected  by  abnormally 
strong  currents  and  winds,  with  an  adequate  entrance  not  blocked 
by  immovable  sand-banks  or  rocks,  such  as  Plymouth  Sound, 
naturally  takes  much  less  artificial  work  to  make  it  safe  and  con- 
venient for  shipping  than  does  a  more  open  position.    Likewise 


EXPOSITION  OF  PROCESSES 


22$ 


the  mouth  of  a  broad  and  deep  river  is  more  easily  converted  into  a 
well-protected  harbour  entrance  than  a  mere  indentation  of  the 
coast  line. 

The  usual  method  employed  in  protecting  the  entrance  to  a 
harbour  is  to  screen  it  from  strong  currents  and  heavy  seas  by 
concrete  piers  and  breakwaters.  The  accompanying  diagrams  will 
make  clear  the  broad  outline  of  the  principles  involved. 

When  the  sea-bed  of  the  proposed  harbour  site  has  been  carefully 
surveyed  by  divers,  the  nature  and  direction  of  the  piers  and  break- 


FiG.  30.  Fig.  31. 

Fig.  30. — A  protected  river  mouth. 

Fig.  31. — Colombo  (Ceylon).  A  semi-artificial  harbour  formed  by  the 
construction  of  three  breakwaters  and  aided  by  the  configuration  of  the 
coastline. 


waters  is  decided  upon.  First  of  all,  after  the  plans  have  been 
drawn,  light  temporary  piers  are  erected.  For  this  purpose  screw- 
piles  are  often  employed  to  support  the  staging.  These  are  the  long 
iron  columns,  with  a  large  screw-thread  on  the  bottom  end,  so 
frequently  used  to  support  seaside  piers.  They  are  put  down  into 
the  sea-bed  and  screwed  round,  and  so  driven  deep  into  the  ground 
just  as  a  screw  is  driven  into  a  piece  of  wood.  In  some  cases, 
however,  the  ordinary  pile,  a  metal  or  wood  column  with  a  pointed 
end,  is  used.  When  this  is  the  case,  instead  of  being  screwed  into 
the  sea-bed  they  are  hammered  in  like  an  ordinary  nail  into  wood. 


2  26    COMPOSITION  OF  TECHNICAL  PAPERS 

Many  of  my  readers  will,  doubtless,  be  familiar  with  the  working 
of  a  pile-driver,  having  perhaps  seen  it  in  operation  at  one  of  the 
seaside  resorts,  where  the  wooden  piles  of  the  groynes  used  to 
prevent  the  loss  of  sand  and  shingle  caused  by  the  tide,  the  wind, 
and  the  waves,  are  almost  constantly  being  replaced  by  the  aid  of 
the  huge  hammer.  It  consists  of  a  vertical  wooden  frame,  up  and 
down  which  slides  a  heavy  block  of  iron,  called  a  monkey.  This 
weight  is  hoisted  to  the  top  of  the  frame  by  means  of  ropes  attached 
to  a  winch;  when  near  the  summit,  a  catch  automatically  releases 


Fig.  32. — A  Pile-driver,  The  metal  block  or  "monkey"  is  shown  shaded. 
When  it  has  been  hauled  to  the  top  of  the  guide  it  is  automatically  released, 
and  falls  on  to  the  head  of  the  pile. 


the  weight  from  the  ropes  which  are  hoisting  it,  and  the  arrange- 
ment is  such  that  it  falls  upon  the  head  of  the  pile,  driving  it  into  the 
sea-bed  with  an  action  analogous  to  that  of  a  hammer  (see  Fig.  32). 
The  temporary  staging  usually  consists  of  a  roughly  constructed 
pier,  up  and  down  which  railway  tracks  are  laid  so  that  the  trolleys 
and  travelling-cranes  handling  the  huge  concrete  blocks  can  move 
with  quickness  and  safety.  When  this  has  been  built,  the  work  of 
levelling  the  sea-bed,  so  that  the  foundations  of  the  concrete  pier 


EXPOSITION  OF  PROCESSES  227 

or  breakwater  may  be  solid,  commences  in  earnest.  This  is  mostly 
carried  out  with  the  aid  of  diving-bells  and  pneumatic  tools.  As 
this  portion  of  the  operations  has  alread}'^  been  dealt  with  in  previous 
chapters  (see  pp.  11 6-1 3  7)  no  further  description  is  necessary. 

Next  comes  the  herculean  task  of  making  the  large  number  of 
immense  concrete  blocks  required  for  the  actual  construction  of 
the  permanent  piers  and  breakwaters.  Concrete,  which  is  formed 
by  mixing  stones,  either  whole  or  crushed,  with  sand  and  Portland 
cement  in  suitable  proportions,  is  a  material  which  is  being  used 
more  and  more  every  day  for  purposes  of  construction.  When  it 
is  being  used  for  large  harbour  works,  the  blocks  are  mostly  "  made 
on  the  premises."     There  are  several  different  ways  of  mixing  con- 


MADRAS 


Fig.  33. — Madras.     An  artificial  harbour  on  an  exposed  coast-line,  formed 
by  the  construction  of  two  breakwaters,  converging  at  their  outer  ends. 

Crete  and  forming  it  into  blocks  on  a  large  scale,  but  the  essential 
features  of  all  are  the  same,  the  difference  being  only  in  the  actual 
method  of  work.  Here  I  shall  describe  the  concrete-making  ar- 
rangements employed  at  the  Gibralter  Dockyard  Extension  Works, 
which  cost  Great  Britain  several  millions  sterling. 

A  network  of  narrow-gauge  railway  lines  were  first  laid  down  to 
facilitate  the  conveyance  of  the  various  ingredients  to  and  from 
the  works.  At  one  end  huge  crushers  broke  up  the  stone  brought 
in  by  the  railway  froni  the  quarries.  The  trucks  were  made  to 
run  up  an  incline  to  the  top  of  the  machines.  The  stone  was  then 
tipped  into  the  crushers,  to  emerge  a  few  minutes  later,  crushed  to 
the  requisite  degree  of  fineness,  through  a  shoot  into  more  trucks 
waiting  for  it  below.  When  sufficient  of  these  were  filled,  they 
were  coupled-up  into  a  train  and  drawn  away  to  the  block-making 
works. 


2  28    COMPOSITION  OF  TECHNICAL  PAPERS 

The  process  employed  for  making  the  concrete  blocks  is  most 
interesting.  On  an  elevated  platform  stood  heaps,  which  were 
constantly  being  replenished,  of  all  the  necessary  ingredients — 
cement,  sand,  and  crushed  stone.  At  regular  intervals  along  this 
platform  were  conical-shaped  holes  or  bins  into  which  an  army  of 
workmen  shovelled  the  proper  proportion  of  each  ingredient. 
When  filled,  a  signal  was  made  to  a  man  under  the  platform,  who 
promptly  released  the  bottom  of  the  bin,  and  the  mass  fell  through 
by  its  own  weight  into  a  mixer  placed  directly  underneath.  The 
mixers  consisted  of  boxes  which  were  made  to  revolve  eccentrically 
on  two  pivots.  Water  was  then  added,  and  the  boxes  revolved 
for  a  certain  time  to  mix  thoroughly  the  contents.  When  this  had 
been  done  the  boxes  were  opened  over  tip-trucks  waiting  below, 
and  the  muddy  looking  mixture  slid  into  them.  The  trucks  were 
then  run  off  along  one  of  the  lines  of  rails  to  the  block- making 
moulds,  which  covered  acres  of  ground.  These  were  merely 
wooden  cases,  which  formed  the  wet  concrete  into  square  blocks 
and  held  them  until  dry  and  hard. 

In  order  to  show  the  capacity  of  big  concrete-making  works, 
which,  it  must  be  borne  in  mind,  are  merely  temporary  arrange- 
ments lasting  only  so  long  as  the  work  of  construction  continues,  it 
is  sufficient  to  point  out  that  at  McCall  Ferry,  Pennsylvania,  where 
a  huge  concrete  dam  has  recently  been  thrown  across  the  Susque- 
hanna river,  the  works  were  capable  of  turning  out  4000  tons  of 
concrete  a  day,  and  that  20,000  tons  of  material  was  kept  in  stock. 

We  now  arrive  at  the  actual  constructive  stage  in  the  building 
of  harbour-piers  and  breakwaters.  The  temporary  staging,  erected 
over  where  the  permanent  pier  is  to  be  built,  has  already  been  run 
out  from  the  shore,  and  on  its  deck  railway  tracks  have  been  laid 
so  that  the  train-loads  of  concrete  blocks  can  be  moved  out  over 
the  water  as  the  work  proceeds.  The  supply  of  concrete  blocks  is 
sufficient  to  commence,  and  the  sea-bed  has  been  levelled  and  pre- 
pared by  divers  and  workmen  in  diving-bells.  There  are,  however, 
two  other  important  pieces  of  mechanism  which  have  not  yet  re- 
ceived attention — the  titan  and  goliath  cranes.  These  p)owerful 
appliances  are  used  for  lifting  the  concrete  blocks  from  the  trucks 
and  lowering  them  into  their  places  under  water. 

The  drivers  of  these  cranes,  which  are  all  worked  and  moved 
backwards  and  forwards  along  the  tracks  by  steam,  are  in  constant 
telephonic  communication  with  the  divers  adjusting  and  fixing  the 


EXPOSITION  OF  PROCESSES 


229 


concrete  blocks  under  water,  and  also  with  the  workmen  levelling 
the  sea-bed  from  the  diving-bells.  It  will  therefore  be  seen  that 
the  precise  moment  and  position  for  lowering  the  blocks  is  deter- 
mined over  the  telephone  wires  from  the  divers  waiting  below  to 
guide  them  into  their  places. 

These  huge  concrete  blocks,  often  weighing  50  tons  each,  are 
built  up  into  the  wall  just  like  ordinary  bricks.  Sometimes  they 
are  held  in  position  by  iron  staples  embedded  in  the  concrete  and 
made  to  dovetail  together,  and  at  others  merely  by  cement.  The 
shape  of  the  wall,  which  is  built  in  tiers,  depends  upon  the  power 
of  the  wind  and  sea  which  it  will  have  to  withstand.  The  most 
usual  form,  however,  is  shown  in  Fig.  34.  The  broad  base  gives 
additional  strength,  and  the  curved  outer  facing  tends  to  throw  off 
the  spray  when  the  waves  beat  against  them.     Inside  the  harbour 


Fig.  34. 


-Section  of  a  breakwater  or  sea-wall,  showing  the  curved  outer 
facing. 


the  walls  forming  the  actual  quays  become  almost  perpendicular 

so  that  vessels  can  lay  close  alongside,  while  the  face  of  breakwaters 

exposed  to  exceptionally  heavy  or  searching  seas  is  often  given  a 

much  greater  slant  in  order  that  the  enormous  force  of  the  breakers 

may  not  be  exerted  at  the  moment  of  impact,  as  would  be  the  case 

with  a  wall  perpendicular  or  nearly  so,  but  expended  more  gradually 

on  the  concrete  incline.     For  the  purpose  of  sea-defence,  however, 

granite  blocks  are  often  used  instead  of  concrete  for  the  facings  of 

the  wall  on  account  of  their  greater  strength,  but  where  the  work 

is  an  extensive  one  the  additional  cost  is  frequently  prohibitive, 

and  resort  is  had  to  "ferro-concrete,"  which  is  nothing  more  than 

the  ordinary  concrete  "reinforced"  by  having  a  network  of  iron 

rods  embedded  to  hold  it  together. 
16 


230    COMPOSITION  OF  TECHNICAL  PAPERS 

The  Foundations  of  Bridges 

One  of  the  most  difficult  parts  of  a  bridge  to  construct  is  undoubt- 
edly the  foundations,  and  it  is  exactly  this  part,  and  this  part  only, 
which  falls  to  the  lot  of  the  submarine  engineer.  Let  us  confine 
our  attentions,  therefore,  to  the  laying  of  these  foundations  by  the 
methods  most  frequently  adopted. 

Much  depends  upon  the  depth  of  water  and  the  nature  of  the 
river-bed.  It  frequently  happens  that  not  only  is  the  water  deep, 
but  many  feet  of  loose  mud  and  clay  cover  the  harder  and  more  solid 
stratum  on  which  the  actual  foundations  of  the  bridge  must  rest. 
To  get  down  on  to  the  river-bed  and  clear  this  away  is  therefore 
the  chief  difficulty  to  be  faced.     Recourse  is  usually  had  to  a 


Fig.  35. — Large  bridge  caisson  and  airlock.     (Description  in  text.) 


"caisson,"  or  large  iron  box,  inside  which,  when  sunk  on  to  the 
river-bed,  work  can  be  carried  on,  and  which  will  itself  eventually 
form  a  portion  of  the  foundations.  The  use  here  of  a  diagram  will 
simplify  the  task  of  describing  the  construction  of  a  caisson,  and 
the  manner  in  which  it  is  used  in  conjunction  with  an  air-lock. 

The  caisson  is  built  of  steel  plates  riveted  together,  and  half-way 
down  the  interior  is  a  steel  floor  {A),  from  which  an  air-tight  shaft 
{B)  leads  up  to  the  surface  of  the  water  (C).  The  two  chambers 
{D)  are  filled  with  concrete  in  order  to  make  the  caisson  sink  as 
deep  as  possible  into  the  mud  of  the  river-bed  by  its  own  weight; 
but  the  large  working  chamber  (£)  is  open  at  its  lower  end,  and  has 
a  sharp  edge  all  round  to  enable  it  to  cut  into  the  mud  and  clay. 


EXPOSITION  OF  PROCESSES  231 

The  air-lock  (F),  which  is  fitted  by  an  air-tight  joint  to  the  top  of 
the  caisson  shaft,  has  been  described  in  an  earlier  chapter. 

The  modus  operandi  is  simple.  The  whole  caisson  is  lowered 
on  to  the  river-bed,  and  the  edge  of  the  bottom  or  working  chamber 
immediately  cuts  into  the  soft  mud  or  clay  to  a  depth  of  several 
feet.  When  it  has  settled  down  as  far  as  it  will  go  of  its  own  weight, 
which  by  the  way  is  very  considerable  owing  to  the  concrete  already 
filling  the  two  upper  chambers,  air  is  pumped  in  through  the  shaft, 
and  the  water  is  thus  prevented  from  entering  the  working  chamber 
of  the  caisson. 

The  air-lock  at  the  top  of  the  shaft  enables  men  and  buckets  of 
dirt  to  be  passed  up  from  the  working  chamber,  resting  on  the 
river-bed,  to  the  temporary  staging  above  the  surface  without 
allowing  any  air  to  escape.  It  will  easily  be  seen  that  if  this 
arrangement  of  air-tight  doors  was  not  made,  the  moment  the  air- 
pressure  in  the  caisson  was  released  by  men  getting  in  or  out,  the 
water  would  rush  up  and  fill  the  working  chamber. 

When  the  caisson  has  settled  down  as  far  as  it  will  go  into  the 
bed  of  the  river,  men  descend  through  the  air-lock  into  the  working 
chamber,  and  commence  removing  the  mud  and  clay  from  the 
inside.  As  this  work  proceeds,  the  caisson  gradually  sinks  deeper 
and  deeper,  until  its  edge  reaches  a  hard  stratum  capable  of  forming 
a  solid  and  lasting  foundation. 

When  this  has  been  accomplished,  the  whole  interior  of  the  work- 
ing chamber  and  the  shaft  leading  to  the  surface  is  filled  up  with 
concrete,  thus  forming  a  huge  concrete  block  in  a  steel  casing.  But 
the  work  does  not  always  end  here,  for  the  shaft — which,  however, 
is  no  longer  a  shaft,  but  has  become  a  column  of  concrete  and  steel — 
is  encased  with  stone  blocks  built  up  on  the  roof  of  the  caisson, 
thus  forming  the  enormously  strong  stone  piers  with  a  steel  and 
concrete  core  which  we  see  supporting  so  many  bridges. 

Among  other  submarine  constructive  works  must  be  mentioned 
the  laying  of  sewerage  outfall  pipes  in  the  sea,  and  electric  cables, 
gas  and  water  mains  on  the  beds  of  rivers.  Although,  compared 
with  the  building  of  harbours,  breakwaters,  piers  and  bridges,  they 
are  but  insignificant  undertakings,  their  importance  and  utility 
to  almost  everyone  cannot  be  denied. 

Many  readers  will  have  noticed  when  walking  along  the  seashore 
at  low  tide  in  the  vicinity  of  towns,  large  iron  pipes,  supported  by 
wooden  trestles  well  embedded  in  the  sand  or  shingle,  running 


232    COMPOSITION  OF  TECHNICAL  PAPERS 

down  the  foreshore  and  disappearing  into  the  sea.  Sometimes  the 
pipes  are  embedded  in  concrete,  but  more  often  than  not  they  are 
left  bare  and  merely  held  in  position  by  stout  wooden  piles  driven 
into  the  sea-bed.  These,  then,  are  outfall  pipes  which  carry  the 
sewerage  some  distance  into  the  sea,  only  releasing  it  when  the  tide 
is  ebbing  so  that  it  may  be  carried  out  and  distributed  by  the  cur- 
rents of  the  ocean. 

Few  people  realise,  however,  that  the  laying  of  these  pipes, 
joining  them  together,  and  securing  them  in  position,  is  often  a  task 
of  considerable  difficulty.  In  some  places  quicksands  have  to  be 
spanned  and  in  other  rocks  levelled  in  order  that  these  pipes  may  be 
run  out  at  the  correct  angle  at  the  most  convenient  spot  some  little 
distance  from  the  sea-front  of  the  town 
which  they  serve.  If,  for  instance,  the 
set  of  the  tide  comes  from  the  south-west, 
as  it  does  on  many  parts  of  the  south  coast 

I  °  ■ j-sJ  of  England,  these  pipes  are  generally  laid 

— ' — ^ ^      so  as   to  incline   in   the  same  direction. 

Fig.  36.— Sewerage  rp^is  is  done  with  the  primary  object  of 
pipe   on   trestle  founda-  1  •        -^         •       r       .1  .1 

^Jqjj  makmg  it  easier  for  the  sewerage  to  leave 

the  pipes  when  the  tide  is  ebbing. 

The  formation  of  the  wooden  piles  or  trestles  on  which  these  pipes 
rest  is  shown  in  Fig.  36,  from  which  it  will  at  once  be  seen  that  the 
pipes  are  prevented  from  sinking  into  the  sand  by  the  wooden  cross- 
pieces,  and  from  being  moved  to  the  right  or  left  by  the  perpen- 
dicular piles  driven  deep  into  the  sea-bed. 

About  the  laying  of  electric  cables,  gas  and  water  mains,  on  the 
beds  of  rivers  little  need  be  said,  for  the  methods  are  very  similar 
to  those  employed  in  sewerage  outfall  work.  There  are,  however, 
many  other  "odd  jobs"  which  come  within  the  province  of  con- 
structive submarine  engineering,  such  as  the  laying  and  repairing  of 
ships'  moorings,  cleaning  and  repairing  sluice-valves  and  dock- 
gates,  and  sinking  cylinders  in  wells,  etc.,  but  needless  to  say  none 
of  these  has  the  same  importance  as  pier,  bridge,  and  harbour  con- 
struction. 


EXPOSITION  OF  PROCESSES  233 

The  Construction  of  a  Large  Reflecting  Telescope^ 

George  Ellery  Hale 

[A  clear  explanation  of  an  unusual  process.  The  ele- 
ments to  be  noted  particularly  are  the  distinct  division 
of  material  and  the  careful  combining  of  the  descriptive 
and  the  narrative  parts.  Several  plates  illustrating  the 
article  have  been  omitted  in  reprinting,  but  references  to 
them  in  the  text  have  been  retained.] 

The  grinding  and  polishing  of  a  60-inch  mirror  involve  a  variety 
of  operations,  described  in  detail  in  Ritchey's  memoir  On  the 
Modern  Reflecting  Telescope  and  the  Making  and  Testing  of  Optical 
Mirrors,*  the  most  authoritative  treatise  on  the  subject.  A  brief 
account  of  these  operations,  taken  in  large  part  from  the  above 
source,  may  be  of  interest  here. 

It  is  first  necessary  to  obtain  a  suitable  disk  of  glass.  The  disk 
(of  plate  glass)  made  by  the  French  Plate  Glass  Works,  of  St. 
Gobain,  France,  for  the  reflecting  telescope  of  the  Solar  Observatory 
is  60  inches  in  diameter,  8  inches  thick,  and  weighs  a  ton.  It  must 
be  remembered  that  the  requirements  for  a  large  mirror  are  very 
different  from  those  for  a  lens  through  which  light  is  to  pass.  The 
mirror  disk  is  merely  a  sffpport  for  the  thin  silver  film  on  its  front 
surface,  from  which  the  light  is  reflected  without  entering  the  glass. 
For  this  reason  the  great  perfection  of  a  lens  disk  is  not  necessary. 
Nevertheless,  the  glass  must  be  free  from  striae  and  other  evidences 
of  irregularity  of  structure.  It  should  contain  no  large  bubbles, 
though  a  few  small  ones,  if  they  do  not  lie  on  the  surface,  are  not 
objectionable.  The  most  important  condition,  however,  is  freedom 
from  strain  caused  by  imperfect  annealing.  Evidences  of  strain 
are  detected  by  a  test  with  polarized  light.  Such  a  test,  however, 
cannot  be  final,  as  an  incident  in  the  history  of  a  great  telescope 
objective  illustrates.     The  disk  had  been  carefully  annealed  and 

'chapter  XXIII  of  The  Study  of  Stellar  Evolution  (University  of  Chicago 
Press,  1908).  Reprinted  by  permission  of  the  publishers.  Use  of  the  article 
was  suggested  by  Professor  J.  H.  Atkinson,  Iowa  State  College  of  Agriculture 
and  Mechanic  Arts. 

*  Published  by  the  Smithsonian  Institute.     [Author's  note.] 


234    COMPOSITION  OF  TECHNICAL  PAPERS 

was  supposed  to  be  suitable  for  its  purpose.  During  the  process 
of  grinding  it  flew  to  pieces,  on  account  of  internal  strain,  the  serious 
nature  of  which  had  not  been  recognized  in  the  test  with  polarized 
light. 

It  may  not  be  obvious  why  the  disk  must  be  so  thick,  when  its 
sole  purpose  is  to  support  the  thin  film  of  silver  on  its  accurately 
figured  face.  Great  thickness,  however,  is  absolutely  essential, 
to  diminish  the  effects  of  bending  due  to  the  weight  of  the  glass 
and  to  temperature  changes.  The  thickness  of  a  mirror  should  not 
be  less  than  one-eighth  or  one-seventh  of  the  diameter.  Even 
with  such  thickness  a  special  support  system  is  necessary  to  prevent 
flexure. 

Glass  is  chosen  in  preference  to  other  materials  for  telescope 
mirrors  because  of  its  uniformity  of  structure,  comparative  ease 
of  working,  and  capacity  for  a  high  polish.  Its  lightness,  when 
compared  with  such  substances  as  speculum  metal  (formerly  em- 
ployed for  telescope  mirrors),  is  an  important  advantage.  Further- 
more, a  surface  of  pure  silver,  first  used  by  Foucault,  reflects  a 
much  larger  proportion  of  light  than  poHshed  speculum  metal. 

The  grinding-machine,  designed  and  constructed  by  Ritchey  for 
his  work  on  the  6o-inch  mirror,  is  shown  in  Plate  XCII.  The  glass 
disk  rests  on  a  heavy  cast-iron  turn-table,  carried  by  a  vertical 
steel  shaft.  Between  the  lower  surface  of  the  glass  (ground  flat) 
and  the  turn-table  are  two  thicknesses  of  Brussels  carpet,  which 
form  an  admirable  support  during  the  grinding  and  polishing  process. 
The  edge  of  the  glass  is  ground  true  by  means  of  a  rapidly  rotating 
iron  face-plate,  held  against  the  disk  while  the  turn-table  is  slowly 
rotated.  The  cutting  material  is  powdered  carborundum  carried 
down  between  the  glass  and  the  face-plate  by  a  slow  stream  of 
water.  After  the  edge-grinding  is  completed,  the  two  faces  of  the 
glass  are  ground  plane  and  parallel,  before  the  process  of  making 
one  of  these  surfaces  concave  is  undertaken. 

The  grinding-tools  employed  for  this  work  are  circular  plates 
of  cast-iron,  strongly  ribbed  on  the  back,  and  divided  into  a  series 
of  small  squares  on  the  grinding  surface,  by  two  sets  of  parallel 
grooves,  planed  at  right  angles  to  one  another.  The  tool  rests  on 
the  surface  of  the  glass,  though  in  Plate  XCIII  it  is  shown  sus- 
pended from  the  lever  arm,  employed  to  swing  the  heavy  tools  into 
or  out  of  position.  During  the  grinding  the  disk  is  slowly  rotated 
and  the  tool,  also  kept  in  rotation,  is  moved  over  its  surface  in  a 


EXPOSITION  OF  PROCESSES  235 

series  of  strokes  from  four  to  eight  inches  in  length,  by  means  of  the 
arm  shown  above  the  disk  in  Plate  XCIII.  On  its  right-hand 
extremity  this  arm  terminates  in  a  steel  shaft,  which  moves  back 
and  forth  through  a  swiveled  bearing  supported  on  an  adjustable 
slide.  In  this  way  the  position  of  the  grinding- tool  on  the  disk 
can  be  changed  laterally,  so  as  to  bring  the  stroke  across  the  centre 
of  the  glass  or  near  the  edge.  If  it  is  found,  for  example,  that  the 
centre  is  being  cut  away  too  rapidly,  the  tool  is  moved  near  the  edge 
and  the  grinding  continued  there  until  the  error  is  corrected.  The 
tool  is  not  kept  at  any  one  position  for  a  great  length  of  time,  to 
avoid  producing  low  zones  in  the  glass. 

For  the  grinding  process,  various  grades  of  carborundum  are 
prepared  in  the  following  way:  The  powdered  carborundum  is 
mixed  with  water  and  thoroughly  stirred.  After  settling  for  two 
minutes  the  coarse  particles  reach  the  bottom  of  the  bucket  and  the 
liquid,  containing  "two-minute"  carborundum  and  the  finer  grades, 
is  siphoned  off  into  another  bucket.  After  the  contents  of  the 
second  bucket  have  been  allowed  to  stand  four  minutes,  the  liquid 
is  poured  off  and  the  "two-minute"  carborundum  at  the  bottom 
of  the  bucket  is  set  aside  for  fine  grinding  purposes.  In  the  same 
way,  carborundum  which  has  remained  in  suspension  for  periods 
up  to  one  hundred  and  twenty  minutes,  or  even  longer,  is  prepared. 
These  very  fine  grinding  materials  are  used  to  give  the  smooth  and 
almost  polished  surface  obtained  after  the  grinding  with  coarser 
carborundum  is  completed. 

A  perfectly  true  Brown  &  Sharpe  steel  straight-edge  is  used  to 
determine  whether  the  surface  of  the  glass  is  approximately  plane. 
When  it  is  found  to  be  sufficiently  so  for  the  preliminary  work, 
the  fine  grinding  is  commenced,  beginning  with  two-minute  car- 
borundum and  continuing  with  finer  grades.  In  this  work  the  iron 
grinding-tool  is  counter-poised  by  placing  weights  on  a  lever  arm 
connected  by  a  shaft  with  the  tool.  The  pressure  is  reduced  from 
one-third  pound  to  the  square  inch  for  the  five-  or  ten-minute  car- 
borundum, to  about  one-twelfth  pound  per  square  inch  for  the 
one-hundred-and-twenty-  and  two-hundred-and-forty-minute  car- 
borundum. Unless  this  precaution  is  taken  there  is  a  great  danger 
of  scratching  the  glass. 

After  being  fine  ground,  the  back  of  the  mirror  is  polished  with 
rouge  in  the  manner  described  later.  No  great  pains  are  taken  with 
this  surface,  although  it  is  made  very  nearly  plane,  and  is  then 


236   COMPOSITION  OF  TECHNICAL  PAPERS 

polished  so  as  to  permit  silvering  (Plate  XCIV).  It  is  desirable 
to  silver  the  back  of  the  mirror,  as  well  as  the  front,  in  order  to 
prevent  temperature  changes  from  affecting  the  two  surfaces  in 
unequal  degree. 

The  front  surface,  after  it  has  been  given  a  plane  figure,  is 
ready  to  be  made  concave.  For  this  purpose  a  convex  iron  tool, 
of  suitable  curvature,  is  employed.  In  the  case  of  the  6o-inch 
mirror  the  radius  of  curvature  is  50  feet.  The  curvature  of  the 
tool,  and  also  of  the  glass,  is  tested  from  time  to  time  by  a  sphero- 
meter.  This  consists  of  a  tripod,  with  a  micrometer  screw  at  its 
center,  which  permits  the  deviation  of  the  surface  of  a  plane  to  be 
accurately  determined.  After  the  desired  curvature  has  been 
secured,  the  fine  grinding  is  carried  to  a  point  where  the  surface  is 
very  smooth  and  ready  for  polishing. 

The  polishing  and  figuring  are  done  by  means  of  a  tool  built  up 
of  narrow  strips  of  wood,  saturated  with  paraffine  to  prevent  change 
of  figure.  The  face  of  this  tool  is  covered  with  squares  of  rosin,  of 
a  certain  degree  of  hardness,  which  can  be  determined  only  by 
experience.  The  rosin  squares  are  finally  coated  with  a  thin  layer 
of  beeswax,  which  forms  the  polishing  surface.  The  soft  wax  is 
very  useful,  since  small  hard  particles  that  may  happen  to  be 
present  in  the  polishing  material  are  likely  to  bed  themselves  in  it, 
thus  reducing  the  danger  of  scratches.  As  a  preliminary  to  polish- 
ing, the  tool  is  placed  in  contact  with  the  glass  disk  and  pressed 
against  it,  by  weights  placed  on  the  back,  so  that  it  may  acquire 
the  same  curvature  as  the  surface.  After  pressing  for  some  hours, 
until  the  wax  squares  appear  smooth  and  bright  in  all  parts,  the 
polishing  may  begin.  This  is  accomplished  by  moving  the  tool 
over  the  rotating  glass,  by  the  main  arm  of  the  machine,  as  in  the 
case  of  the  grinding  process.  The  polishing  material  is  powdered 
jewelers'  rouge,  used  commercially  for  polishing  plate  glass.  The 
fine  rouge  is  separated  from  impurities  and  coarser  particles  by  a 
washing  process  similar  to  that  used  for  carborundum.  The  rouge, 
mixed  with  distilled  water,  is  applied  to  the  surface  of  the  glass 
by  means  of  a  wide  brush  of  cheese-cloth. 

The  greatest  precautions  must  be  taken  throughout  the  polishing 
process  to  avoid  scratches.  For  this  purpose  the  room  in  which  the 
work  is  done  is  fitted  up  in  such  a  way  as  to  eliminate  danger 
from  dust.  In  the  polishing-rooms  of  the  Solar  Observatory 
optical  shops  (Plate  XCV)  the  plastered  walls  and  ceilings  are 


EXPOSITION  OF  PROCESSES  237 

heavily  varnished,  and  a  canvas  screen  is  hung  above  the  glass, 
to  protect  it  from  any  falling  particles.  The  cement  floor  is 
painted,  and  kept  wet  when  the  polishing  is  in  progress.  The 
windows  are  double  and  carefully  sealed,  outer  air  being  admitted 
to  the  room  through  a  cheese-cloth  filter.  The  temperature  is 
maintained  constant,  within  two  or  three  degrees,  by  means  of 
a  hot- water  furnace,  controlled  by  a  thermostat.  The  motor, 
driving-shaft,  and  apparatus  for  varying  the  speed  of  the  grinding- 
machine,  are  carefully  inclosed,  only  the  slow-moving  belt  coming 
out  into  the  room.  No  one  is  permitted  to  enter  the  room  except 
the  optician,  who  wears  a  surgeon's  gown  and  cap.  By  observing 
such  precautions  the  work  may  be  continued  for  months  without 
producing  even  microscopic  scratches  in  the  glass  surface. 

We  may  now  assume  that  the  glass  has  been  polished,  after 
receiving  an  approximately  spherical  surface.  It  then  becomes 
necessary  to  apply  a  more  accurate  test  than  the  spherometer  per- 
mits. For  this  purpose  the  glass  is  turned  into  a  nearly  vertical 
position,  where  it  is  supported  by  a  steel  edge-band  (Plate  XCV). 
An  artificial  star,  consisting  of  a  hole  about  )^oo  of  an  inch  in 
diameter  illuminated  by  an  acetylene  lamp  or  other  brilliant 
source  of  light,  is  placed  at  the  centre  of  curvature,  50  feet  from  the 
glass  surface.  The  light  from  the  artificial  star  then  falls  upon  the 
disk  and  is  reflected  back  so  as  to  form  an  image  close  beside  the 
pin-hole.  If  the  surface  is  perfectly  spherical,  it  will  appear,  when 
examined  by  the  eye  placed  at  this  point,  to  be  brilliantly  and 
uniformly  illuminated.  With  an  eye-piece,  the  image  of  the  pin- 
hole will  then  be  perfectly  sharp,  showing  the  most  minute  details 
or  irregularities  of  the  hole  itself. 

It  is  much  more  probable,  however,  that  the  surface  will  have 
many  zonal  errors.  To  detect  and  interpret  these,  the  "knife- 
edge  test,"  due  to  Foucault,  is  employed.  If  all  the  zones  come  to 
a  focus  at  the  same  point,  and  a  knife  edge  is  moved  across  this 
point,  while  looking  at  the  glass,  the  light  will  be  cut  off  instantly 
from  all  parts  of  the  disk.  If,  however,  the  curvature  of  certain 
zones  is  greater  or  less  than  the  average  curvature,  these  zones  will 
resemble  projecting  or  receding  rings  on  an  otherwise  uniformly 
bright  surface.  The  effect  is  as  though  the  light  were  shining  from 
one  side,  producing  an  appearance  of  relief  by  lights  and  shadows. 
The  test  is  so  sensitive  that  an  error  of  3^  0  0  0  0  0  part  of  an  inch  can 
be  detected.     If,  for  example,  the  finger  is  placed  for  a  few  moments 


238    COMPOSITION  OF  TECHNICAL  PAPERS 

on  the  glass,  the  heating  of  the  surface  will  cause  a  swelling  easily 
to  be  detected  by  the  knife-edge  test. 

The  process  of  figuring  consists  in  removing  the  high  and  low 
zones  by  means  of  the  polishing  tool,  the  stroke  and  position  of 
which  must  be  modified  in  accordance  with  the  results  of  the  knife- 
edge  test.  After  a  perfectly  spherical  form  has  been  obtained  in 
this  way,  the  difficult  process  of  changing  the  spherical  to  a  para- 
boloidal  surface  is  begun.  As  is  well  known,  the  parallel  rays 
from  a  star,  falling  on  a  spherical  surface,  will  not  be  brought  to  a 
focus  at  a  central  point,  but  in  an  irregular  figure,  called  a  "caustic." 
A  paraboloid,  however,  brings  all  parallel  rays  to  a  single  focus,  and 
produces  a  perfect  stellar  image.  In  the  case  of  the  6o-inch 
mirror,  which  has  a  focal  length  of  25  feet,  the  paraboloid  is  deeper 
than  the  sphere  at  the  center  of  the  disk  by  a  quantity  less  than 
%ooo  of  an  inch.  Months  of  figuring  are  required,  however,  to 
produce  this  small  difference,  because  of  the  necessity  of  giving  each 
zone  of  the  paraboloid  precisely  the  right  curvature.  In  testing 
the  surface  from  the  center  of  curvature,  the  measured  radius  of 
each  narrow  zone  of  the  mirror  (the  other  parts  being  covered  by  a 
cardboard  screen)  must  correspond  with  the  calculated  radius. 
The  extreme  difficulty  of  accomplishing  this  may  be  appreciated 
when  it  is  remembered  that  the  deviation  of  any  zone  from  the 
surface  of  a  perfect  paraboloid  must  not  be  greater  than  % 00 0000 
of  an  inch  which  would  correspond  to  a  change  of  ^00  of  an  inch 
in  the  radius  of  curvature. 

When  parallel  light  is  available,  the  difficulties  of  securing  a 
perfectly  satisfactory  test  of  a  paraboloidal  mirror  are  greatly 
reduced.  In  this  case  the  mirror,  when  seen  from  its  focal  plane 
(25  feet  from  the  glass,  or  pne-half  the  radius  of  curvature)  ap- 
pears like  a  uniformly  illuminated  plane  surface  when  a  perfectly 
paraboloidal  form  has  been  obtained.  This  method  of  testing 
with  parallel  light  has  been  developed  by  Ritchey,  and  was  used  by 
him  to  secure  the  last  degree  of  perfection  in  the  figure  of  the  60-inch 
mirror. 

As  already  explained  the  problem  of  mounting  a  large  mirror 
is  quite  as  serious  as  that  of  figuring  it.  It  is  necessary,  in  the  first 
place,  to  support  the  mirror  in  such  a  way  that  it  will  retain  its 
form,  without  bending,  in  any  position  of  the  telescope.  Further- 
more, it  must  be  held  so  that  it  will  not  slip  laterally,  since  the 
slightest  change  in  the  position  of  the  mirror  with  respect  to  the  tube 


EXPOSITION  OF  PROCESSES  239 

will  cause  a  displacement  of  the  star  images  6n  the  photographic 
plate.  The  mirror,  thus  supported,  must  be  carried  at  the  lower 
end  of  a  tube,  of  skeleton  construction,  open  at  the  top,  and  so 
mounted  that  it  can  be  pointed  toward  any  part  of  the  heavens  and 
made  to  follow  the  apparent  motion  of  the  stars  by  rotation  about  an 
axis  parallel  to  the  axis  of  the  Earth.  Strength  and  stability  of  the 
mounting,  freedom  from  flexure,  perfection  of  optical  and  mechan- 
ical construction  and  adjustment,  and  the  greatest  precision  of  driv- 
ing— all  these  conditions  must  be  met  before  a  large  reflector  can 
be  expected  to  give  satisfactory  results,  in  the  more  exacting  depart- 
ments of  photographic  work. 

The  difficulties  thus  presented  have  been  most  successfully 
solved  by  Ritchey,  whose  design  for  the  mounting  of  the  60-inch 
mirror  is  shown  in  Plate  XCVI.  The  telescope  tube  is  hung 
beween  the  arms  of  a  massive  cast-iron  fork,  which  is  bolted  to  the 
upper  end  of  the  polar  axis.  This  axis,  a  hollow  forging  of  nickel 
steel,  is  inclined  at  an  angle  corresponding  to  the  latitude  of  Mount 
Wilson  (34°  13')  and  thus  rendered  parallel  to  the  axis  of  the  earth 
Leveling  screws,  by  which  the  base  of  the  mounting  is  supported 
on  its  pier,  permit  this  adjustment  to  be  made  with  great  precision. 
In  order  to  relieve  the  great  friction  of  this  axis  on  the  upper  and 
lower  bearings  in  which  it  lies,  a  hollow  steel  float,  10  feet  in  dia- 
meter, is  bolted  to  its  upper  end,  just  below  the  fork.  This  float  dips 
into  a  tank  filled  with  mercury.  Thus  the  entire  instrument  is 
floated  by  the  mercury,  and  in  this  way  the  friction  on  the  bearings 
is  reduced  to  a  minimum. 

The  60-inch  mirror  rests  at  the  lower  end  of  the  tube,  on  a  sup- 
port system  consisting  of  a  large  number  of  weighted  levers,  which 
press  against  the  back  of  the  glass  and  distribute  the  load.  A  simi- 
lar series  of  weighted  levers  around  the  circumference  of  the  mir- 
ror provide  the  edge  support.  The  path  of  the  rays  from  the  star 
may  be  as  shown  in  Plate  XCVII,  Figs,  i,  2,  3,  or  4.  In  the  first 
arrangement  (the  Newtonian  telescope),  the  parallel  rays,  after 
striking  the  mirror,  are  reflected  back  and  would  come  to  a  focus 
at  a  point  just  beyond  the  end  of  the  tube.  They  are  intercepted, 
however,  by  a  plane  mirror  of  silvered  glass,  which  turns  them  at 
right  angles  and  forms  the  image  on  the  photographic  plate,  which 
is  mounted  on  the  side  .of  the  tube  near  the  upper  end.  In  this 
case  the  focal  length  of  the  instrument  is  25  feet,  and  the  image  is 
formed  without  secondary  magnification. 


240    COMPOSITION  OF  TECHNICAL  PAPERS 

If,  however,  it  is  desired  to  secure,  for  certain  classes  of  work,  the 
advantages  of  a  greater  focal  length,  a  dififerent  arrangement  is 
adopted.  The  upper  section  of  the  tube,  bearing  the  plane  mirror, 
is  removed,  and  a  shorter  section  substituted  for  it.  This  carries  a 
hyperboloidal  mirror,  which  returns  the  rays  toward  the  center  of 
the  large  mirror  and  causes  them  to  converge  less  rapidly.  They 
then  meet  a  small  plane  mirror,  supported  at  the  middle  of  the  tube 
near  its  lower  end,  which  sends  them  to  one  of  the  following  instru- 
ments, mounted  in  the  focal  plane:  (i)  a  double-slide  plate  holder, 
carrying  a  sensitive  plate,  for  the  photography  of  the  Moon,  planets, 
bright  nebulae,  etc.,  with  an  equivalent  focal  length  of  loo  feet 
(Fig.  3);  (2)  a  spectrograph  mounted  in  place  of  this  photographic 
plate,  in  which  case  a  convex  mirror  of  different  curvature  is 
employed,  and  the  equivalent  focal  length  is  80  feet  (Fig.  4);  or 
finally  (3)  a  third  convex  mirror  may  be  used  and  the  plane  mirror 
inclined  so  as  to  form  the  star  image  (after  sending  the  light  down 
through  the  hollow  polar  axis)  on  the  slit  of  a  powerful  spectro- 
graph, of  13  feet  focal  length,  mounted  on  a  pier  in  a  constant- tem- 
perature chamber  (Fig.  2).  In  this  case  the  equivalent  focal 
length  is  1 50  feet. 

The  telescope  is  moved  in  right  ascension  or  declination  by 
electric  motors,  controlled  from  the  floor  of  the  observing-room. 
The  driving-clock  moves  the  telescope  in  right  ascension  by  means  of 
a  worm-gear,  10  feet  in  diameter,  carried  by  the  polar  axis.  The 
cutting  of  the  teeth  of  this  worm-gear  is  a  mechanical  operation 
requiring  the  highest  precision  of  workmanship.  Each  tooth  was 
spaced  off  by  means  of  a  finely  divided  circle  attached  to  the  polar 
axis,  and  read  with  a  microscope.  The  rotating  cutter  was  driven 
by  an  electric  motor.  After  all  the  teeth  had  been  cut,  the  worm 
and  worm-gear  were  ground  together  for  many  hours,  until  all 
slight  residual  errors  had  been  eliminated.  The  operation  was 
completed  with  jewelers'  rouge,  which  leaves  a  smooth  and  highly 
polished  surface. 

All  of  the  heavy  parts  of  this  mounting  were  made,  after  Ritchey's 
designs,  by  the  Union  Iron  Works  Company,  of  San  Francisco. 
They  were  then  shipped  to  Pasadena,  where  the  mounting  has  been 
erected  in  the  Solar  Observatory  shop  (Plate  XCVIII).  Here  the 
worm-gear  was  cut,  and  all  of  the  smaller  parts,  including  the  driv- 
ing-clock, setting-circles,  slow  motions,  motors,  etc.,  are  being 
fitted  and  adjusted.    All  of  these  parts  were  made  in  the  Observa- 


EXPOSITION  OF  PROCESSES  241 

tory  instrument  shop,  which  is  equipped  with  the  best  machinery- 
obtainable  for  work  of  this  kind  (Plate  XCIX). 

As  soon  as  this  mounting  has  been  completed,  the  60-inch  mirror 
will  be  put  in  place  and  the  telescope  thoroughly  tested,  by  actual 
photography  of  the  heavens.  It  will  then  be  necessary  to  transport 
the  instrument  to  Mount  Wilson — an  operation  of  considerable 
difl&culty,  as  several  of  the  castings  are  very  large,  and  weigh  about 
five  tons  each. 

The  building  for  the  60-inch  reflector  is  of  steel  construction 
throughout  (Plate  C).  The  thin  inner  walls  will  be  shielded  from 
the  Sun  by  outer  walls,  and  air  will  be  permitted  to  circulate  in  the 
space  between  the  two.  The  dome,  60  feet  in  diameter,  will  be 
rotated  by  an  electric  motor,  either  rapidly,  when  passing  from  one 
part  of  the  heavens  to  another,  or  at  a  slow  uniform  rate,  of  such  a 
speed  as  to  keep  the  opening  (15  feet  wide)  constantly  opposite  the 
end  of  the  telescope  tube,  when  it  is  following  a  star.  The  observer, 
when  photographing  in  the  principal  focus,  will  stand  on  a  platform 
suspended  from  the  dome  and  rotating  with  it.  The  double-slide 
plate-carrier,  with  which  stars  and  nebulae  will  be  photographed,  is 
similar  to  that  used  with  the  Yerkes  telescope  (Plate  XVII). 


Refining  Crude  Petroleum^ 
Walter  Sheldon  Tower 

[Professor  Tower  has  succeeded  admirably  in  doing  a 
very  difficult  thing,  in  reducing  a  complex  process  to  its 
essential  stages.  To  appreciate  fully  the  difficulties  of 
keeping  to  the  main  channel  in  an  exposition  of  an  intri- 
cate process,  the  reader  should  know  what  is  omitted 
as  well  as  what  is  included;  acareful  analysis  of  the  chap- 
ter can  not,  however,  fail  to  reveal  how  unified  and  well 
balanced  it  is.  The  plan  of  the  article,  without  being 
obtrusive,  is  distinctly  evident.     The  following  elements 

1  Chapter  VII  of  The  Story  of  Oil  (D.  Appleton  and  Company,  1909)- 
Reprinted  by  permission  of  the  publishers.  The  use  of  the  selection  was 
suggested  by  Grose's  Specimens  of  English  Composition  (Scott,  Foresman 
and  Company). 


242    COMPOSITION  OF  TECHNICAL  PAPERS 

should  also  be  noted:  (i)  the  skilful  sketching  in,  early 
in  the  chapter,  of  the  whole  process,  (2)  the  method  of 
constructing  the  explanation  of  one  step  of  the  process 
upon  the  explanation  of  an  earlier  step,  (3)  the  use  of 
analogies  and  of  concrete  language  generally,  and  (4) 
the  smooth  interweaving  of  divisions,  even  the  intro- 
duction and  the  conclusion  being  linked  neatly  with  the 
preceding  and  the  following  chapters  respectively.] 

The  enormous  supplies  of  petroleum  in  this  country  never 
had  any  great  industrial  value  until  some  method  of  purification 
or  refining  was  invented.  The  early  attempts  to  use  the  crude  oil 
for  domestic  lighting  purposes  in  various  places  were  invariably 
unsuccessful,  on  account  of  the  sooty,  smoking  flame,  and  the 
extremely  disagreeable,  nauseous  odor.  Use  as  an  illuminant  was 
the  only  avenue  of  development  which  seemed  to  offer  any  real 
possibilities,  but  it  was  absolutely  necessary  that  the  quality  of  the 
oil  should  be  improved  by  the  removal  of  these  objectionable 
features^  if  its  use  were  to  become  general. 

Purification  of  petroleum  was  done  in  a  rough  way  many  years 
before  the  modern  process  was  perfected,  but  never  on  a  very  im- 
portant scale.  The  medicinal  oils  used  in  European  countries  two 
centuries  ago  were  generally  subjected  to  some  process  of  distilla- 
tion or  filtration.  Refined  illuminating  oil  from  the  Galician  dis- 
tricts was  introduced  in  the  early  part  of  the  last  century,  and  soon 
after  that  time  filtering  through  charcoal  was  tried  in  this  country 
to  remove  the  odor  and  improve  the  general  appearance  of  the 
crude  oil.  The  first  important  refining  plant  in  the  world,  however, 
was  probably  erected  in  the  Baku  district  about  1823.  It  con- 
sisted of  an  iron  still  having  a  capacity  of  forty  buckets,  and  said 
to  give  about  sixteen  buckets  of  so-called  "white  naphtha"  from 
each  charge.  This  refined  oil  found  a  ready  sale  at  the  great  Rus- 
sian fair  at  Nishni  Novgorod,  presumably  to  be  used  in  lamps. 

Petroleum  refining  in  this  country  began  in  a  small  way  about 
1855,  with  Kier's  experiments  to  turn  his  medicinal  oil  to  some 
more  valuable  use.  The  manufacture  of  so-called  "paraffin  oils" 
from  coal  and  shale  had  increased  so  rapidly  in  the  decade  following 
1850  that  there  were  some  fifty  or  sixty  establishments  in  the  eastern 


EXPOSITION  OF  PROCESSES  243 

part  of  the  United  States  when  Drake's  well  was  opened.  Kier's 
results  had  already  shown  clearly  enough  that  paraffin  oils  could 
be  secured  more  easily  from  petroleum  than  from  coal  or  shale,  and 
more  cheaply  also  if  the  supply  of  petroleum  were  large  enough. 
The  prospect  of  securing  petroleum  in  large  quantities  by  following 
Drake's  example  made  the  entire  shale  oil  industry  totter.  The 
owners  of  the  refineries,  many  of  which  were  then  only  fairly  started, 
saw  themselves  facing  ruin,  until  a  simple  and  easy  salvation 
appeared  in  converting  their  plants  into  petroleum  refineries. 
Thus,  the  latter  industry  was  able  to  profit  immediately  from  the 
existence  of  this  large  number  of  ready-made  establishments. 

Kier's  first  attempts  at  refining  petroleum  had  given  him  a 
"carbon  oil"  distillate,  distinctly  superior  to  the  crude  oil,  but 
far  from  being  perfect.  The  strong  odor  still  persisted  and 
brought  a  storm  of  complaints  from  the  consumers.  General 
dissatisfaction  was  expressed  also  on  account  of  the  rapidity 
with  which  the  oil  turned  black,  and  on  account  of  the  formation 
of  a  hard  crust  on  the  wick  which  interfered  with  the  free  burn- 
ing of  the  flame.  As  a  result  the  "carbon  oil"  gained  favor 
slowly,  despite  the  fact  that  an  army  of  canvassers  and  selling 
agents  spread  over  the  country  to  boom  its  use.  Something  had 
to  be  done  to  place  petroleum  oil  on  as  satisfactory  a  basis  as 
were  the  shale  and  coal  oils.  Distillation  alone  would  evidently 
never  suffice.  Chemical  treatment  to  purify  the  products  after 
distillation  was  tried  and  soon  demonstrated  that  successive  manip- 
ulations with  solutions  of  alkali  and  acid  would  remove  the  chief 
objectionable  features.  These  improvements,  already  familiar 
abroad,  had  been  introduced  here  about  the  time  Drake  went  to 
the  oil  regions.  Therefore,  as  soon  as  his  well  was  struck,  the  re- 
fining of  petroleum  was  in  a  condition  to  expand  and  drive  the 
shale  oil  industry  out  of  existence  in  short  order. 

The  most  important  process  in  the  refining  of  petroleum,  as 
it  is  carried  on  to-day,  consists  essentially  of  two  parts:  first,  heating 
the  oil  in  a  still  until  it  vaporizes  in  the  same  way  as  boiling  water 
passes  into  steam;  and  second,  condensing  these  vapors  just  as 
steam  condenses  on  cold  objects.  The  successful  separation  of  the 
different  products  depends  on  the  fact  that  each  of  the  many 
compounds  composing  crude  oil  has  its  own  particular  boiling  point, 
and  thus  allows  gradual  heating  to  carry  on  the  process  of  division, 
or  fractional  distillation,  as  it  is  called.    The  stills  where  the  crude 


244   COMPOSITION  OF  TECHNICAL  PAPERS 

oil  is  heated,  the  condensers  where  the  vapors  of  successive  divisions 
are  returned  to  the  liquid  form,  and  the  tanks  for  storing  the  refined 
products,  therefore,  represent  the  important  parts  of  the  skeleton 
of  every  refinery. 

The  early  refineries  were  mainly  small  plants  with  a  few  vertical 
iron  stills  resembling  giant  cheese  boxes,  and  having  a  capacity  of 
twenty-five  to  seventy-five  barrels  each.  As  the  industry  expanded, 
however,  and  made  constantly  increasing  demands  on  the  capacity 
of  the  refineries,  larger  and  larger  stills  were  introduced.  A 
horizontal  cylinder  still  was  found  to  offer  various  advantages  over 
the  old  cheese  box  style,  and  the  cylinder  form,  with  a  capacity  of 
about  600  barrels,  is  the  type  now  generally  used  in  this  country. 

Each  still  may  have  its  own  condenser,  or  several  stills  may 
be  connected  with  a  common  condenser,  although  the  former 
arrangement  is  preferable.  In  either  case  the  condenser  is  the 
same,  consisting  of  coils  of  three-  or  four-inch  pipe  several  hundred 
feet  long,  and  ordinarily  kept  cool  by  thousands  of  gallons  of  water 
pumped  over  them  daily.  The  hot  vapors  entering  the  condenser 
from  the  still  come  in  contact  with  the  cold  pipe  and  return  to  liquid 
form,  in  the  same  way  as  steam  on  a  winter  day  will  collect  on  the 
cold  glass  of  a  window  and  trickle  down  the  pane  in  tiny  streams  of 
water.  The  refined  product  of  a  dozen  condensers  may  be  turned 
into  a  single  receiving  tank  until  the  limit  of  its  capacity  is  reached, 
and  then  other  similar  tanks  are  pressed  into  service. 

Between  the  condenser  and  the  receiving  tanks,  the  distilled 
oil  has  to  pass  through  the  stillhouse  and  undergo  the  keen  scrutiny 
of  the  stillman,  on  whose  skill  the  success  of  the  entire  process 
depends.  The  condensed  distillates  make  their  entrance  to  the 
stillhouse  through  a  V-shaped  tube,  such  as  are  commonly  inserted 
in  drain  pipes  to  prevent  the  passage  of  sewer  gas,  and  which  serves 
much  the  same  purpose  here.  A  vertical  pipe  on  the  condenser 
side  of  the  V  allows  the  uncondensable  gases  from  the  still,  that  is, 
those  vapors  which  will  condense  only  at  very  low  temperature, 
either  to  escape  into  the  air  or  to  be  led  away  to  be  burned  under 
the  still  from  which  they  came.  The  condensed  distillate,  now  in 
the  liquid  form  again,  passes  through  the  V  tube  and  enters  the 
stillhouse  in  what  is  called  the  separating  box,  a  triangular,  cast- 
iron  affair.  A  glass  door  on  one  side  of  the  box  enables  the  stillman 
to  watch  both  the  color  of  the  oil  and  the  size  of  the  stream  as  it 
enters  the  box.    In  this  way,  from  the  knowledge  of  long  experi- 


EXPOSITION  OF  PROCESSES  245 

ence,  he  knows  how  to  regulate  his  fires  under  the  stills,  and  from 
occasional  samples  of  the  distillate  he  can  determine  when  a 
different  grade  of  oil  has  begun  to  vaporize  in  the  still  and  is  coming 
through  the  condenser.  Shutting  one  valve  and  opening  another 
close  at  hand  turns  the  stream  into  a  different  receiving  tank. 
So  the  process  goes  as  long  as  separation  is  possible,  or  until  some 
special  requirements  make  it  desirable  to  stop  the  distillation  at  a 
certain  point. 

The  actual  process  of  distillation  consists  in  carefully  separating 
the  different  hydrocarbon  compounds  which  make  up  the  crude 
petroleum.  These  "fractions,"  as  the  different  compounds  are 
called,  are  determined  more  or  less  arbitrarily  by  their  weight  as 
compared  with  an  equal  bulk  of  water,  and  by  the  ease  with  which 
they  give  off  inflammable  vapors. 

Distillation  may  be  done  by  what  is  known  as  the  intermittent 
process,  in  which  the  major  part  of  the  operation  is  carried  on  in 
one  still  heated  to  successively  higher  temperatures  by  gradually 
increasing  the  fires  beneath  it.  This  method  is  most  commonly 
used  in  the  United  States.  Distillation  may  also  be  done  by  the 
continuous  process,  in  which  the  crude  oil  is  pumped  through  a  series 
of  stills,  each  succeeding  one  being  heated  to  a  constant  temperature 
higher  than  that  of  the  one  preceding. 

In  the  intermittent  process,  the  crude  oil  in  the  still  is  subjected 
to  a  gradually  increasing  temperature,  so  that  the  different  frac- 
tions pass  off  to  the  condenser  in  the  order  of  their  volatility. 
The  lighter  and  more  volatile  compounds,  that  is,  those  boiling  at 
low  temperatures,  are  vaporized  first,  the  heavy,  less  volatile 
compounds  not  appearing  until  the  highest  temperatures  are 
reached.  Different  petroleums  vary  so  widely  in  character,  and 
the  number  of  possible  products  is  so  large  that  each  kind  re- 
quires special  treatment  to  secure  the  particular  products  for 
which  it  is  best  adapted.  The  distilling  business,  therefore, 
becomes  decidedly  intricate  when  examined  in  detail,  and  a  high 
degree  of  skill  must  be  exercised  in  manipulating  the  process  so 
that  it  will  yield  the  largest  quantity  and  best  quality  of  the 
valuable  oils. 

The  general  character  of  the  treatment  can  be  shown  by  com- 
paring the  two  common  processes  known  as  "running  to  tar" 
and  "running  to  cylinder  stock."     The  main  difference  between 

these  two  processes  is  that  the  former  gives  the  largest  possible 
16 


246    COMPOSITION  OF  TECHNICAL  PAPERS 

yield  of  illuminating  oils  and  a  small  yield  of  heavier  products  for 
lubricating.  The  second  process  is  intended  to  yield  a  maximum 
amount  of  the  lubricating  oils,  with  the  illuminating  oils  of  second- 
ary consideration.  In  general  therefore,  one  process  is  the  direct 
reverse  of  the  other  in  so  far  as  its  chief  object  in  view  is  concerned. 

Both  processes  start  with  crude  oil  heated  in  the  still,  and  the 
vapors  passing  off  into  the  condenser.  The  most  volatile  of  these 
vapors  begin  to  appear  before  much  of  any  heat  is  applied  to  the 
still.  They  can  be  condensed  only  by  special  processes  at  tem- 
peratures near  the  freezing  point,  consequently  in  the  ordinary 
course  of  distillation  they  pass  off  into  the  air  through  the  escape 
pipe  from  the  condenser  or  are  led  under  the  still  to  serve  as  fuel. 
The  first  distillate  which  condenses  and  passes  through  the  V  tube 
to  the  stillhouse  is  a  clear,  colorless  light  oil,  but,  as  the  process 
goes  on,  the  stream  of  oil  entering  the  separating  box  becomes 
heavier,  and  the  color  gradually  changes  through  yellow  to  darker 
shades.  The  stillman  tests  the  density  of  the  oil  from  time  to 
time,  and  on  the  basis  of  these  tests  and  the  color,  he  turns  the 
streams  into  different  tanks,  by  simply  closing  and  opening 
convenient  valves. 

The  stream  passing  through  the  separating  box  is  continuous  as 
long  as  the  still  contains  any  oil  which  can  be  vaporized,  hence  the 
stillman's  divisions  of  the  stream  of  distillates,  or  his  "  cuts,"  as  they 
are  called,  are  an  exceedingly  important  part  of  the  process.  The 
first  cut  is  usually  made  when  oils  of  the  naphtha  class  cease  to 
appear.  The  second  cut  is  the  illuminating  oil.  In  the  "running 
to  tar"  process,  the  method  known  as  "cracking"  is  employed 
after  about  two-thirds  of  the  cut  of  illuminating  oil  has  passed 
over,  its  object  being  to  increase  the  proportion  of  illuminating  oils 
obtained. 

The  exact  changes  which  take  place  in  the  still  during  this 
"cracking"  process  are  only  partly  understood.  The  process 
was  discovered  accidentally  in  1861  by  a  stillman  at  Newark, 
N.  J.,  who  left  his  post  one  day  after  about  half  the  contents 
had  passed  off,  building  a  strong  fire  under  the  still  to  last  until  he 
returned,  as  he  expected,  a  half  hour  later.  Several  hours  elapsed, 
however,  before  he  did  return,  and  then,  to  his  amazement,  he 
found  issuing  from  the  condenser  a  lighter  distillate  than  was  being 
obtained  when  he  left,  whereas  it  should  normally  have  been  much 
heavier.     Such  an  entirely  unheard  of  thing  led  immediately  to 


EXPOSITION  OF  PROCESSES  247 

experiments,  in  which  it  was  found  that  a  portion  of  the  heavy 
distillate,  normally  coming  through  the  condenser  last,  had  con- 
densed on  the  cooler  upper  portion  of  the  still,  and  dropping  back 
on  the  highly  heated  liquid  had  encountered  a  temperature  hot 
enough  to  cause  decomposition  of  some  sort,  so.  that  a  lighter  oil 
was  the  final  result.  Many  different  devices  have  been  invented 
to  aid  in  this  cracking  process,  and,  though  some  refineries  use  it 
but  little,  cracking  has  been  of  enormous  benefit  in  the  case  of 
certain  petroleums,  naturally  yielding  only  a  small  percentage  of 
kerosene,  yet  rich  in  the  grades  heavier  than  kerosene,  and  not 
heavy  enough  to  be  high  quality  lubricating  oils.  By  cracking, 
many  of  these  intermediate  grades  are  broken  up,  and  become  valu- 
able illuminating  oil. 

After  cracking  has  given  as  much  kerosene  as  can  be  secured 
the  fires  are  checked,  and  the  tar  process  stops  so  far  as  the  first 
still  is  concerned.  A  certain  amount  of  thick  residue,  or  "tar," 
always  remains  in  the  still  and  must  be  removed  before  the  still 
can  receive  another  charge  of  crude  oil.  This  tar  usually  goes  to  a 
second  still,  where  further  distillation  gives  lubricating  oils,  parafl5n 
wax,  and  coke.  The  cuts  of  naphtha  and  illuminating  oils  are  also 
either  redistilled  or  subjected  to  further  treatment  to  purify  them 
and  separate  them  into  different  commercial  grades. 

The  process  known  as  "running  to  cylinder  stock"  is  essentially 
the  same  as  the  other  up  to  the  point  where  cracking  would  begin, 
except  that  it  is  usually  applied  to  crude  oils  naturally  adapted  to 
the  manufacture  of  lubricants.  The  important  difference  consists 
in  heating  the  still  by  free  superheated  steam  within,  as  well  as  by 
the  usual  fire  underneath  the  still.  The  presence  of  the  steam 
causes  a  more  even  distribution  of  the  heat,  and  more  completely 
vaporizes  the  voltatile  lighter  oils  from  the  whole  charge  without 
having  to  subject  it  to  such  a  high  temperature.  When  the  distil- 
late in  this  process  appears  too  heavy  for  kerosene,  instead  of  the 
cracking  treatment,  a  third  cut,  known  as  the  "wax  slop,"  is  often 
made.  Different  methods  of  handling  the  cut  yield  special  brands 
of  oil  for  a  great  variety  of  purposes,  from  the  headlight  oil  of  loco- 
motives to  the  thin  "spindle  oils"  used  to  lubricate  light  machinery. 
The  entire  elimination  of  the  cracking  process  leaves  a  greater 
residue  in  the  still  after  the  "wax  slop"  cut  is  made  and  this  residue, 
known  as  "cylinder  stock,"  forms  the  basis  for  the  manufacture  of 
a  host  of  lubricating  oils. 


248    COMPOSITION  OF  TECHNICAL  PAPERS 

The  Russian  process  of  continuous  distillation  differs  from  the 
American  method  only  in  using  a  series  of  a  dozen  or  more  stills, 
each  of  which  is  heated  to  a  definite  steady  temperature.  The 
crude  oil  passing  from  one  still  to  another  encounters  these  suc- 
cessively high  temperatures,  which  correspond  to  the  boiling 
points  of  the  different  petroleum  products.  Each  still  constantly 
gives  off  a  distillate  of  uniform  character,  while  the  series  of  stills 
gives  the  same  range  of  distillates  as  are  obtained  by  the  gradual 
application  of  increased  heat  in  the  intermittent  system.  The  pos- 
sibility of  supplying  the  crude  oil  to  the  stills  as  fast  as  the  distillates 
pass  off  results  in  important  economies  of  time,  less  waste  of  fuel, 
and  a  minimum  of  injury  to  the  plant  by  avoiding  the  cooling  and 
reheating  of  the  still.  This  process,  however,  is  not  well  adapted 
to  American  conditions  because  of  differences  in  the  nature  of  the 
crude  oils,  and  in  the  products  most  desired.  The  American 
refiner,  in  general,  aims  to  produce  as  much  kerosene  or  lubricating 
oils  as  possible,  whereas  in  Russia  the  enormous  demand  for  the 
residuum,  or  astatki,  for  fuel  makes  it  nearly  as  valuable  as  any 
other  product.  There  is,  therefore,  little  inducement  to  increase 
the  yield  of  kerosene  and  reduce  the  quantity  of  residuum  by 
employing  the  cracking  process,  which  can  be  done  only  in  inter- 
mittent distillation. 

The  first  distillates  obtained  from  the  crude  oil  by  either  pro- 
cess usually  have  to  be  redistilled  or  purified  before  they  can 
be  used.  Any  sulphur  which  is  present  must  be  removed  either 
in  the  first  process  or  subsequently.  One  method  makes  use  of 
copper  oxide  in  the  first  condenser,  or  in  a  specially  constructed 
still,  the  sulphur  by  chemical  union  being  removed  in  the  form  of  a 
copper  sulphide,  from  which  the  copper  can  be  reclaimed  and  used 
over  and  over.  Another  method  makes  the  separation  by  treating 
the  distillates  successively  with  sulphuric  acid,  caustic  soda  and 
litharge  in  agitator  tanks  built  for  the  purpose,  the  removal  in  this 
case  being  in  the  form  of  a  sulphide  of  lead.  This  treatment  for 
sulphur  is  one  of  the  most  important  and  yet  most  troublesome 
processes  of  all,  since  the  presence  of  a  very  small  percentage  of 
sulphur  imparts  a  highly  disagreeable  odor  to  any  distillate.  No 
product  can  be  sold  until  the  last  trace  of  sulphur  has  been  removed. 

The  naphtha  distillate,  where  obtained  in  important  quantities, 
may  be  roughly  separated  into  different  grades,  or  cuts,  known  as 
gasoline,  commercial  naphtha,  and  benzine.     When  the  division 


EXPOSITION  OF  PROCESSES  249 

is  made  by  the  stillman,  as  they  come  from  the  condenser,  washing 
with  acid,  water,  caustic  soda,  and  water  again,  in  the  metal  agita- 
tors, to  purify  and  deodorize  is  the  only  further  treatment  necessary 
before  they  are  ready  for  shipment.  More  often,  however,  all  the 
naphtha  distillate  goes  into  a  single  cut  as  it  comes  from  the  con- 
denser, is  subjected  as  a  whole  to  the  deodorizing  and  purifying 
treatment  and  is  then  redistilled  and  divided  into  the  three  frac- 
tions mentioned  above.  This  redistillation  of  the  naphtha  is  done 
in  a  special  still  heated  by  steam,  and  with  the  outlet,  through  which 
the  vapors  reach  the  condenser,  rising  for  some  distance  before  it 
actually  enters  the  condenser  coil.  This  arrangement  is  intro- 
duced to  prevent  any  liquid  from  being  carried  over  into  the  con- 
denser with  the  gas.  The  condenser  for  the  naphtha  still  also 
differs  from  the  others  in  having  two  coils  of  pipe,  the  first  of  which 
has  a  "back  trap,"  or  pipe  leading  back  to  the  still,  so  that  any 
heavier  oils  present,  condensing  quickly,  will  be  returned  to  the 
still.  The  main  body  of  the  naphtha  distillate  is  condensed  in  the 
second  coil  of  pipe,  and  is  cut  into  standard  grades  by  the  usual 
separating-box  method,  but,  in  order  to  secure  the  very  lightest  of 
the  products,  it  is  necessary  to  use  a  third  coil  surrounded  by  a 
freezing  mixture  of  salt  and  ice.  The  different  cuts  obtained  from 
this  distillation  are  immediately  ready  for  use  as  soon  as  tested  to 
prove  their  quality. 

The  distillate  of  illuminating  oil,  or  kerosene,  as  we  know  it,  if 
used  just  as  it  comes  from  the  original  still,  has  all  the  disadvantages 
which  Kier's  "carbon  oil"  presented,  charring  the  wicks,  giving  off 
an  unpleasant  odor,  and  rapidly  turning  to  a  dark  color  after  stand- 
ing, all  owing  to  the  presence  of  various  impurities.  The  illuminat- 
ing "cut,"  therefore,  is  given  the  same  sort  of  purification  treat- 
ment as  is  applied  to  the  naphtha.  Testing  and  grading  for  sale 
then  complete  the  last  stages  in  the  production  of  kerosene. 

The  manufacture  of  lubricating  oils,  and  parafiin  or  wax  com- 
plete the  principal  processes  of  refining.  Some  lubricating  oils 
are  produced  by  the  processes  known  as  sunning  or  reducing, 
depending  on  the  evaporation  of  the  lighter  products  either  by  ex- 
posing the  crude  oil  in  open  tanks  or  by  gently  heating  it  with  steam. 
This  method  of  treatment  is  said  to  have  originated  from  the  obser- 
vation that  certain  oils  spilled  on  the  streams  of  the  oil  regions  were 
thickened  by  evaporation,  and  became  fit  for  lubricating  purposes 
without    further    treatment.     Experiments    with    different    oils 


2SO    COMPOSITION  OF  TECHNICAL  PAPERS 

showed  the  possibility  of  making  natural  lubricators  in  this  way 
from  special  grades  of  crude  petroleum.  So-called  "sunned  oils" 
and  "reduced  oils"  are  still  to  be  found  on  the  market,  but  by  far 
the  greater  proportion  of  machine  oils  are  products  of  distillation. 

These  refined  lubricating  oils  come  either  from  the  process  of 
"running  to  cylinder  stock,"  or  from  the  redistillation  of  the 
"  wax  slop"  and  of  the  tar  left  in  the  still  after  cracking  for  kerosene 
is  completed.  These  oils,  in  one  way  or  another,  form  the  basis  of 
all  grades  of  machine  oil  from  the  very  lightest  "spindle  oil"  to 
the  heaviest  grease.  The  processes  of  treatment  differ  only  in 
minor  details  from  those  used  for  the  lighter  oils.  Different  cuts 
are  made,  and  these  cuts,  together  with  varying  methods  of  purifi- 
cation, bleaching  and  filtering,  determine  the  particular  grade  pro- 
duced. In  general,  however,  the  redistillation  of  the  "wax  slop" 
cut  yields  the  major  portion  of  the  light  and  especially  high-grade 
lubricating  oils,  while  the  heavier  grades  come  from  the  cylinder 
stock. 

Paraffin  was  once  regarded  merely  as  a  by-product  of  distilla- 
tion, but  it  is  now  so  widely  used  in  industrial  processes  that  in 
some  refineries  it  is  fully  as  valuable  as  any  of  the  other  pro- 
ducts. Paraffin  is  obtained  from  the  redistillation  of  either  the 
residuum  left  in  the  tar  process  after  cracking  is  completed,  or 
from  the  "wax  slop"  cut  in  the  cylinder-stock  process.  In  either 
case  the  paraffin  distillation  is  carried  on  in  heavy  steel  stills  at 
very  high  temperatures.  The  paraffin  passes  off  in  one  long  stream 
of  distillate,  the  latter  end  of  which  may  be  almost  pure  wax.  It 
then  undergoes  the  same  chemical  purification  as  the  other  products, 
the  only  difference  being  that  the  agitator  must  be  heated  to  pre- 
vent cooling  and  solidification  of  the  wax.  The  subsequent  treat- 
ment, however,  is  much  more  complicated,  consisting  of  a  variety 
of  steps  as  follows:  to  a  settling  tank  where  the  water  is  removed; 
to  a  chilling  tank  where  ammonia  machines  cause  it  to  congeal  and 
crystallize;  to  a  filter  press  which  forces  out  any  oil  remaining,  and 
leaves  only  solid  paraffin;  to  the  melting  tank  to  be  converted  into 
liquid  paraffin  again;  to  the  bone-black  filter  where  all  color  im- 
purities are  removed;  and,  finally,  to  the  second  chilling  tank, 
where  it  is  returned  to  the  crystallized  form  ready  for  the  hydraulic 
presses  which  convert  it  into  cakes  for  shipment. 

From  this  description  it  appears  that  only  two  of  the  important 
products  of  petroleum  are  regularly  obtained  directly  from  the 


EXPOSITION  OF  PROCESSES  251 

first  distillation;  these  are  the  illuminating  oils  and  the  cylinder 
stock,  and  both  of  these  have  to  receive  additional  treatment  subse- 
quently. All  other  products  are  *he  result  of  a  second  distillation 
and  of  chemical  manipulations.  The  percentage  of  the  different 
products  obtained  by  refining  varies  immensely,  depending  both 
on  the  original  character  of  the  crude  oil  and  on  the  special  aims 
of  the  individual  refiner.  Illuminating  oils  run  as  high  as  seventy- 
five  per  cent,  or  eighty  per  cent.,  and  as  low  as  twenty  per  cent,  to 
twenty-five  per  cent.  Lubricating  oils  vary  from  nothing  up  to 
twenty  per  cent.,  or  thirty  per  cent.,  and  the  residuum  and  waste 
may  be  as  high  as  thirty  per  cent,  of  the  whole  volume  of  crude  oil. 
The  residuum,  representing  the  compounds  which  cannot  be  vapor- 
ized by  ordinary  means,  is  not,  however,  all  loss,  because,  whether 
pitch,  coke,  or  asphalt,  according  to  the  character  of  the  crude  oil, 
various  methods  of  treatment  and  utilization  are  devised.  Prac- 
tically nothing  is  lost  except  moisture,  solid  impurities,  and  the 
varying  amounts  of  uncondensed  gases.  Even  the  water  used  in 
washing  the  distillates  is  sent  to  huge  settling  tanks  to  recover  any 
oil  which  may  have  been  included  in  it. 

The  most  volatile  of  these  distilled  oils,  the  naphthas,  are  ex- 
tremely inflammable  liquids,  the  gases  from  which  make  violently 
explosive  combinations  when  mixed  with  air.  The  presence  of  a 
very  small  percentage  of  the  lighter  naphtha  oils  in  illuminating  or 
lubricating  oils  is,  therefore,  a  constant  source  of  danger.  If  such 
oils  are  used  explosions  and  fires  are  sure  to  occur.  The  danger  is 
especially  great  in  the  case  of  naphthas  present  in  kerosene,  the 
most  prolific  cause  of  lamp  accidents  and  fires  in  the  early  days  of 
the  industry.  Continued  complaints  about  the  "  deadly  kerosene," 
as  it  was  frequently  called,  led  to  the  establishment  of  certain 
legal  standards  which  all  illuminating  oils  must  meet.  It  has  con- 
sequently become  customary  to  subject  all  the  distilled  oils  to 
standard  tests  in  order  to  insure  a  uniform  quality  of  the  product. 
Testing  is  now  fully  as  important  a  part  of  the  refining  process  as  is 
distillation  itself,  since  it  is  the  only  safeguard  for  the  interests  of 
both  producer  and  consumer. 

The  lighter  oils  of  the  naphtha  group  are  usually  tested  for 
gravity,  odor,  and  acid  impurity.  The  gravity  test  is  made  with 
the  usual  Baume  hydrometer,  and  on  the  basis  of  this  test  the 
oils  are  graded  for  commercial  purposes,  as  gasoline,  naphtha, 
and  benzine.     The  test  for  odors  is  made  by  simply  saturating  a 


2  5  2  COMPOSITION  OF  TECHNICAL  PAPERS 

cloth  with  the  oil;  as  the  oil  evaporates  from  the  cloth  any  for- 
eign odors  are  readily  detected.  The  presence  of  acid  is  revealed 
by  testing  with  litmus  paper,  which  immediately  turns  red  if  the 
acid  has  not  been  entirely  removed.  Benzines  for  special  purposes, 
as  in  the  manufacture  of  paints  and  varnishes,  also  have  to  be  free 
from  any  of  the  heavier  oils.  The  test  in  this  case  is  made  by  soak- 
ing part  of  a  sheet  of  paper  in  the  benzine,  if  heavier  oil,  like  kero- 
sene, is  present,  a  grease  spot  shows  as  the  volatile  benzine  rapidly 
evaporates;  otherwise  the  whole  sheet  of  paper  presents  the  same 
appearance. 

The  testing  of  kerosene  oils  is  by  far  the  most  important  of  all, 
because  the  conditions  under  which  it  is  used  in  ordinary  lamps  are 
especially  favorable  for  the  occurrence  of  explosions.  Kerosene 
is  tested  for  acid,  sulphur,  gravity,  color,  and  what  is  known  as  the 
"fire  test."  Acid  and  gravity  tests  are  the  same  as  for  naphthas. 
Color  is,  of  course,  determined  by  inspection,  and  furnishes  the 
basis  for  division  of  the  kerosene  into  the  three  grades  common  in 
this  countrj'^:  water  white,  which  is  colorless,  and  is  the  standard  of 
American  kerosene;  prime  white,  of  a  faint  yellow  color;  and  statidard 
or  standard  white,  a  pronounced  yellow.  In  European  countries 
other  grades  are  recognized,  as  many  as  seven  being  commonly  sold 
in  Germany. 

The  fire  tests,  however,  are  the  most  significant  since  they 
determine  the  safe  or  unsafe  character  of  the  kerosene  and  the 
legality  of  its  sale.  Two  fire  tests  may  be  used,  one  of  them  called 
the  "flash  test,"  determining  the  temperature  at  which  the  oil  will 
give  ofif  an  inflammable  vapor  when  heated  artificially,  or  when 
exposed  naturally  to  the  air.  The  other,  known  as  the  "burning 
test,"  determines  the  temperature  at  which  the  oil  will  take  fire  and 
burn  on  the  surface.  The  latter  temperature  is  usually  from  ten  to 
forty  degrees  higher  than  the  "flashing  point,"  and,  since  the 
gravest  dangers  are  from  the  generation  of  explosive  vapors,  the 
flash  test  means  most. 

A  great  number  of  devices  have  been  invented  for  making  the 
flash  test,  the  essential  principle  of  each  being  a  closed  or  open  cup  in 
which  the  oil  is  heated.  A  common  form  of  tester  consists  of  a  cup 
holding  about  the  same  amount  of  oil  as  a  medium-sized  lamp,  the 
cup  being  immersed  in  water  and  heated  carefully  by  heating  the 
water,  on  the  same  principle  as  cooking  in  a  double  boiler.  The 
glass  cover  of  the  cup  has  a  hole  for  a  thermometer  and  another  for 


EXPOSITION  OF  PROCESSES  253 

inserting  a  match  to  ignite  the  vapor.  Kerosene,  to  be  safe  for 
lighting  purposes,  should  have  a  flashing  point  higher  than  any 
temperature  which  it  is  likely  to  reach  under  ordinary  conditions. 
In  most  places  a  flashing  point  of  1 10°  or  higher  is  required  by  law. 
Testing,  however,  usually  begins  as  soon  as  the  thermometer  shows 
the  oil  to  have  a  temperature  or  about  85°  or  90°,  and  continues  at 
intervals  of  every  degree  or  two  until  the  insertion  of  the  match 
causes  the  appearance  of  a  bluish  flame  in  the  cup.  As  soon  as  this 
** flash"  flame  appears  the  reading  of  the  thermometer  indicates 
whether  the  oil  is  up  to  the  required  standard.  Illuminating  oils 
for  special  purposes  such  as  headlight  oil  for  locomotives,  signal 
lamps,  miners'  lamps,  and  so  on,  frequently  have  to  meet  much 
higher  requirements  than  for  ordinary  domestic  use,  but  the  testing 
process  is  the  same. 

Lubricating  oils  are  subjected  to  three  important  tests,  viscosity, 
fire  test,  and  cold  test,  each,  in  a  way,  being  of  vital  significance  in 
determining  the  value  of  the  oil.  The  first,  if  any,  is  perhaps  the 
most  important  since  viscosity  is  the  most  necessary  quality  of  any 
lubricating  fluid.  The  test  may  be  made  in  innumerable  ways,  but 
all  depend  on  the  principle  of  determining  the  length  of  time  required 
for  a  given  quantity  of  the  oil  to  flow  through  a  small  opening.  The 
temperature  at  which  the  test  is  made  depends  on  the  special  use 
for  which  the  individual  oil  is  intended,  ranging  up  as  high  as  212** 
in  the  case  of  cylinder  oils  for  steam  engines. 

The  fire  test  is  necessary  in  the  case  of  most  machine  and  engine 
oils  because  the  heat  from  friction  might  generate  inflammable 
vapors  if  very  volatile  products  were  present.  The  cold  test  is  also 
required  to  determine  the  temperature  at  which  the  oil  would 
become  thick  and  cloudy.  This  test  is  made  by  freezing  the  oil  in  a 
tube,  and  then  as  it  melts,  noting  the  temperature  at  which  it 
begins  to  run.  High-grade  lubricating  oils  have  to  withstand  a 
very  wide  range  of  temperatures;  first  quality  cylinder  oil,  for 
example,  must  have  a  cold  test  as  low  as  55°,  and  it  must  not  flash 
below  550°  Fahrenheit. 

All  these  tests  must  be  made  at  the  refinery,  for  each  lot  of 
distillates  before  they  can  be  approved,  graded,  and  loaded  for 
shipment  to  the  consumer.  If  any  distillate  does  not  "prove 
up,"  it  has  to  go  back  for  further  manipulation  to  remedy  the 
defects,  the  success  or  failure  of  the  tests  depending  largely  on  the 


254   COMPOSITION  OF  TECHNICAL  PAPERS 

skill  of  the  stillman  in  making  his  cuts  as  the  distillate  passes 
through  his  separating  box. 

In  spite  of  its  many  steps  and  intricate  processes  there  is  nothing 
picturesque  or  spectacular  in  petroleum  refining  unless  it  is  in  the 
magnitude  of  the  plant  and  the  very  obscurity  of  the  many  trans- 
formations going  on  everywhere  yet  entirely  unseen.  One  refinery 
is  essentially  the  same  as  every  other  save  in  size,  and  perhaps  in  a 
few  minor  details.  At  a  hundred  refineries  from  the  Atlantic  to  the 
Pacific,  and  from  the  Lakes  to  the  Gulf,  the  same  story  is  repeated 
day  after  day  and  year  after  year,  as  the  invisible  stream  of  oil 
makes  its  journey  step  by  step  through  the  maze  of  pipes,  stills, 
condensers,  and  agitators,  leaving  at  every  turn  a  part  of  its  precious 
burden.  On  the  one  hand,  the  vast  network  of  pipe  lines  binds  the 
refinery  to  thousands  of  wells,  scattered  halfway  across  the  conti- 
nent. On  the  other  hand,  the  world-distributing  system  carries 
the  multitude  of  refined  products  into  the  daily  life  of  every  class  of 
humanity. 


CHAPTER  VIII 
EXPOSITION  OF  IDEAS 

Principles 

The  composition  of  a  technical  description  or  of  a  pro- 
cess-exposition which  really  succeeds  in  its  object  of  re- 
creating in  the  mind  of  the  reader  a  clear  visualization 
of  the  object  described  or  the  process  explained  is  by  no 
means  easy.  But  such  expositions  do  not  present,  on  the 
whole,  as  many  difficulties  as  do  expositions  of  ideas. 
The  reasons  for  this  fact  are  not  hard  to  understand. 
Whatever  the  difficulties  in  technical  description  and 
process-exposition  may  be,  the  problem  is  always  defi- 
nite; the  writer  is  dealing  objectively  with  concrete  facts, 
a  visualization  of  which  he  is  trying  to  create  in  the  mind 
of  the  reader.  In  the  exposition  of  ideas,  on  the  other 
hand,  the  material  with  which  he  deals  is  fundamentally 
abstract,  even  where  concrete  elements  may  enter  in ;  the 
writer  aims,  moreover,  to  create  in  the  reader's  mind  not 
a  mere  visualization  of  things  which  can  be  seen,  but  an 
understanding  of  the  immaterial  and  intangible.  Fur- 
thermore, the  writer  of  exposition  of  ideas  usually  meets 
a  different  attitude  on  the  part  of  his  reader  from  that 
which  the  writer  of  technical  description  and  process- 
exposition  meets.  The  reader  of  these  latter  types  of 
exposition  is  usually  merely  receptive;  the  writer  is  only 
the  medium  through  which  things  that  the  reader  has 
not  himself  seen  are  brought  to  him.     In  most  exposi- 

255 


256    COMPOSITION  OF  TECHNICAL  PAPERS 

tions  of  ideas,  on  the  other  hand,  the  writer  is  more  than 
a  mere  recorder  of  what  he  has  seen;  he  is  also  an  inter- 
preter and  often  the  defender  of  a  proposition ;  and  the 
reader  who  was  willing  to  accept  without  question  the 
accuracy  of  what  the  writer  saw  may  be  quite  unwilling 
to  accept  the  soundness  of  what  the  same  writer  believes. 
In  the  first  case,  it  is  a  question  merely  of  trusting  to 
the  trained  eye  of  an  observer;  in  the  second  case,  it  is  the 
much  more  delicate  matter  of  placing  complete  confi- 
dence in  his  opinions  and  judgment.  For  these  reasons, 
therefore,  the  writing  of  an  exposition  of  ideas  is  more 
difficult  than  that  of  the  simpler  objective  types  of 
exposition. 

The  range  of  expositions  of  ideas  is  much  greater  than 
that  of  the  other  types  of  exposition.  Under  a  classifi- 
cation based  on  the  relation  of  writer  and  reader  many 
are  simple  elucidations  in  which  the  writer  is  the  teacher 
and  the  reader  the  pupil  receptive  to  the  ideas  which 
he  believes  the  writer  capable  of  imparting.  In  this 
simple  type  the  writer  is  merely  a  medium  for  conveying 
to  another  as  clearly  as  possible  a  definite  body  of  uni- 
versally accepted  truths.  Such  an  exposition  is  the 
definition  of  The  Table  of  Single  Potentials  (Student 
Theme,  No.  4,  p.  270).  It  is  obvious  that  the  task  of 
the  writer  of  such  an  explanation  is  a  comparatively 
simple  one  since  he  does  not  have  to  be  concerned  with 
the  soundness  of  the,  ideas  which  he  is  transferring. 
Most  expositions  of  ideas  are  not,  however,  of  this  di- 
dactic type,  but  are  based  fundamentally  upon  proposi- 
tions embodying  the  author's  beliefs  or  opinions.  Ex- 
positions of  belief  or  opinion  vary  widely  from  demon- 
strations of  propositions  based  on  sound  empirical  evi- 
dence and  widely  accepted  to  those  based  on  mere  pre- 


EXPOSITION  OF  IDEAS  257 

sumptive  proofs  and  abstract  reasoning,  and  accepted, 
in  some  cases,  by  the  author  alone.  It  is  evident  that 
the  author's  attitude  toward  the  reader  will  vary  from 
that  of  a  demonstrator  of  hypotheses  which  the  reader 
ought  to  accept  to  that  of  a  supporter  of  beliefs  which 
the  reader  might  reasonably  be  unwilling  to  accept. 
Examples  of  expositions  of  belief  or  opinion  will  be  found 
among  the  student  themes  which  follow  the  text  of  this 
chapter.  The  definition  of  The  Chemical  Engineer  (No. 
6,  p.  274),  for  example,  is  only  an  individual  interpreta- 
tion of  the  function  of  a  chemical  engineer  with  which  we 
may  or  may  not  agree.  Similarly,  we  need  not  accept 
the  truth  of  the  basic  proposition  of  The  Value  of  Tech- 
nical Journalistic  Work  to  the  Engineering  Student  (No.  8, 
p.  276).  Of  the  psychological  basis  of  expositions  of  the 
first  type  mentioned,  those  which  are  merely  elucidative, 
it  need  only  be  said  that  the  writer  should,  of  course, 
have  a  clear,  sound  understanding  of  the  truths  which  it 
is  his  purpose  to  explain.  Expositions  of  belief  and 
opinion  are  more  involved,  and  demand,  therefore,  a  few 
suggestions  concerning  the  logical  matters  of  proposi- 
tion building,  evidence,  and  authority.  Afterwards  the 
problems  of  organizing  the  exposition  of  ideas  will  be 
considered. 

It  has  already  been  said  that  expositions  of  belief  or 
opinion  consist  essentially  of  propositions,  expressed  or 
implied,  together  with  whatever  the  writer  may  have  to 
say  in  support  of  them.  Now  the  world  is  sometimes 
willing  to  accept  a  proposition  without  demanding  the 
supporting  evidence;  but  the  world  does  so  only  because 
it  either  wants  to  believe  the  proposition  or  is  willing  to 
trust  the  authority  of  the  maker  of  the  proposition.  In 
the  latter  case  the  reader  assumes  that  the  proposition 


2  58    COMPOSITION  OF  TECHNICAL  PAPERS 

is  actually  based  on  good  evidence  and  waives  his  claim 
to  the  facts  in  the  case.  But  blind  acceptance  of  author- 
ity is,  fortunately,  the  exception  rather  than  the  rule, 
and  the  soundness  of  a  proposition  may  ordinarily  be 
said  to  vary  directly  with  the  soundness  of  the  evidence 
supporting  it.  "The  man  of  science,"  says  Huxley,  "has 
learned  to  believe  in  justification,  not  by  faith,  but  by 
verification,"  and  one  of  the  most  fundamental  and  strik- 
ing differences  between  an  uneducated  and  an  educated 
man  is  that  the  first  will  build  innumerable  propositions 
on  little  or  no  evidence,  whereas  the  second  will  build  a 
few  propositions  slowly  and  solidly  on  an  abundance  of 
evidence.  It  would  seem,  then,  that  a  proposition  should 
be  supported  upon  sound  evidence  and  subjected  to  as 
wide  a  verification  as  possible. 

A  complete  consideration  of  the  subject  of  evidence  and 
the  induction  of  hypotheses  and  propositions  from  evi- 
dence would  demand  a  course  in  logic.  It  will  be  possible 
here  to  take  up  only  some  of  the  most  general  ideas. 
The  supporting  elements  of  a  proposition  may  be  based 
upon  actual  evidence,  gathered  by  the  writer  or  by 
others,  or  upon  presumptive  evidence.  The  first  is  the 
result  of  actual  observation  and  verification;  the  second 
is  based  upon  logical  reasoning  which  results  in  the  pre- 
sumption of  truths.  It  is  obvious  that  the  soundness  of 
the  first  type  will  depend  upon  the  accuracy  of  the  ob- 
servations, the  typical  quality  of  the  phenomena  ob- 
served, and  the  extent  of  the  verification.  The  sound- 
ness of  the  second  will  depend  upon  the  solidity  of  the 
basis  upon  which  the  built-up  tissue  of  presumptions 
rests  and  upon  the  logic  of  the  reasoning.  Propositions 
may  be  based  entirely  upon  the  personal  observations 
and  reasonings  of  the  author  or  upon  these  evidences 


EXPOSITION  OF  IDEAS  259 

plus  those  gathered  by  other  persons;  often  use  is  made 
of  sub-propositions  which  have  been  long  established 
and  which  are  universally  accepted.  The  citation  of  an 
authority  merely  means  that  the  writer,  unable  person- 
ally to  subject  his  proposition  to  as  many  verifications 
as  he  would  like,  is  depending  upon  another  for  further 
evidence  in  support  of  it.  But  the  citation  of  authorities 
is  often  so  important  a  matter  in  expositions  of  ideas 
that  it  deserves  consideration  in  a  separate  paragraph. 

The  citation  of  an  authority  in  support  of  a  given  belief 
or  opinion  means,  as  has  been  said,  the  tapping  of  a  vein 
of  evidence  wider  and  more  solid  than  that  which  the 
writer  has  personal  access  to.  *  An  authority  is  an  author- 
ity by  virtue  of  the  fact  that  because  of  his  training,  his 
advantageous  position,  his  breadth  of  experience,  and  his 
intellectual  powers,  his  opinions  are  likely  to  be  solidly 
based  and  rationally  presented.  When  we  make  use  of 
his  utterances,  we  are  standing,  so  to  speak,  on  his  shoul- 
ders, and  are  adding  his  great  knowledge  to  our  little. 
Now,  unfortunately,  we  are  likely  in  our  use  of  authori- 
ties to  be  blind  and  non-discriminating,  to  put  equal 
faith  in  all  claimants  to  authority.  For  us  to  do  this  is 
natural,  for  we  can  assume  easily  the  attitude  of  mere 
recipients  of  second-hand  information,  and  we  are,  more- 
over, tempted  to  save  ourselves  investigating  and  think- 
ing. There  is  no  academic  phenomenon  more  generally 
recognized  than  the  blind  faith  of  the  students  in  author- 
ity and  especially  in  printed  authority,  and  no  phrase  is 
more  familiar  to  the  ear  of  the  thesis-instructor  than  the 
wearying,  "Where  can  I  get  a  book  on  the  subject?" 
These  things  are  written  not  to  deprecate  real  authority, 
but  simply  to  warn  against  non-discriminating  faith. 
For  there  are  sham  authorities  as  well  as  real  authorities, 


26o    COMPOSITION  OF  TECHNICAL  PAPERS 

empty-headed  and  untrained  and  shallow  thinkers,  who 
in  this  easy  day  of  much  printing  find  little  trouble  in 
getting  their  books  between  covers.  A  discriminating 
seeker  for  support  of  his  beliefs  will,  therefore,  make  sure 
that  the  authority  whom  he  cites  is  favorably^  and  not 
merely  popularly  known,  and  that  the  author's  training, 
experience,  and  demonstrated  intellectual  powers  entitle 
him  to  his  high  claims. 

A  supplementary  word  on  the  subject  of  authorities 
should,  perhaps,  be  added.  The  honest  and  painstaking 
writer  will  be  careful  in  using  the  opinions  or  words  of 
another  to  indicate  the  source  of  his  borrowings.  No 
attempt  need  be  made  to  ast'ribe  to  any  one  writer  ideas 
which  are  universally  current,  but  for  a  writer  to  fail  in 
other  cases  to  give  credit  to  his  authority  is  for  him  to  be 
guilty  of  literary  theft.  Failure  to  give  the  exact  refer- 
ence, moreover,  cuts  the  reader  ofif  from  continuing  his 
study  in  that  particular  direction.  It  is  always  well, 
therefore,  to  give  as  exact  a  reference  as  possible. 

The  value  of  an  exposition  of  belief  or  opinion  will 
depend,  of  course,  not  only  upon  the  value  of  the  evi- 
dence, primary  or  second-hand,  but  also  upon  the  sound- 
ness of  judgment  exercised  in  making  use  of  the  evidence. 
It  is  perfectly  possible,  as  everybody  knows,  for  a  care- 
less and  illogical  writer  so  to  misuse  good  evidence  as  to 
draw  from  it  conclusions  which  are  quite  distorted.  No 
"rules"  can  be  given  which  will  prevent  an  irrational  and 
untrained  mind  from  such  misoperations;  the  ability  to 
reason  solidly  from  evidence  comes  from  inherent  power 
and  from  long  training.  It  will  be  possible,,  therefore,  to 
point  out  here  only  two  or  three  logical  fallacies  which 
seem  common.  The  first  of  these  is  the  tendency,  al- 
ready hinted  at,  to  base  wide  conclusions  on  too  little 


EXPOSITION  OF  IDEAS  261 

evidence.  This  is  the  characteristic  of  the  immature 
and  loose  thinker;  it  will  be  observed  that,  in  general, 
the  more  powerful  a  man's  intellect,  the  more  slow  will 
he  be  to  reach  a  conclusion,  and  the  more  firmly  estab- 
lished the  conclusion,  once  pronounced,  will  be.  Another 
frequent  fallacy  in  reasoning  comes  from  the  hasty  as- 
sumption that  because  two  phenomena  are  concurrent, 
they  are  therefore  related.  Perhaps  the  most  common 
error,  however,  is  the  familiar  post  hoc  fallacy,  the  as- 
sumption that  because  one  phenomenon  occurs  after 
another  one,  it  therefore  occurs  as  a  result  0}  it.  All 
these  errors  and  many  morein  handling  the  evidence  in 
support  of  a  proposition  the  writer  must  guard  against 
if  he  would  convince  his  readers  that  his  proposition  is 
not  only  based  upon  sound  evidence  but  is  rationally 
built  up  from  that  evidence. 

The  peculiar  difiiculties  presented  by  the  exposition  of 
ideas  lie  not  only  in  the  fundamental  complexities  already 
pointed  out,  but  also  in  those  of  actual  organization. 
The  problems  of  selecting  and  arranging  the  divisions  of 
a  technical  description  and  of  a  process-exposition  are 
seldom  very  difficult  inasmuch  as  both  selection  and  order 
of  parts  are  determined  very  largely  by  the  subject- 
matter  of  the  composition.  In  a  technical  description 
the  order  of  parts  is  suggested  by  the  relationship  of  cer- 
tain physical  details;  in  a  process-exposition  it  is  essen- 
tially chronological.  In  an  exposition  of  ideas,  however, 
since  the  material  dealt  with  is  fundamentally  subjective 
in  nature  and  not  objective,  the  problems  of  selection 
and  arrangement  of  details  are  much  more  difficult.  For 
the  selection  of  parts  no  principles  can  be  laid  down  inas- 
much as  the  writer  must  determine  in  each  case  after  an 
analysis  of  his  problem  just  what  had  best  be  included 

17 


262    COMPOSITION  OF  TECHNICAL  PAPERS 

and  what  omitted.  For  the  arrangement  of  parts — so 
great  is  the  variation  possible — only  the  most  general 
suggestions  can  be  made,  and  these  should  be  understood 
to  be  not  rules  but  general  principles  only. 

A  technical  description  should  be  planned  by  groups  of 
concrete  details,  a  process-exposition  by  stages,  an  ex- 
position of  ideas  by  topics.  These  topics  which  collec- 
tively make  up  the  whole  exposition  will  be  sometimes 
loosely,  sometimes  intimately  related.  For  example,  a 
paper  on  The  Advantages  of  Steel  in  Railway  Car  Con- 
struction will  consist  for  the  most  part  of  an  enumeration 
of  advantages,  each  one  being  made  up  of  a  proposition 
and  its  proof.  Here  the  connection  between  the  topics 
arises  merely  from  the  fact  that  their  functions  are  co- 
ordinate; and  their  relative  position  is  not,  therefore, 
likely  to  be  a  matter  of  very  great  consequence.  In  an 
exposition,  on  the  other  hand,  in  which  the  entire  ener- 
gies of  the  writer  are  bent  toward  the  establishment  of 
a  single  culminating  proposition,  that  proposition  may 
come  as  the  climax  of  a  long  series  of  interlocked  minor 
propositions,  each  resting  upon  its  own  bed  of  evidence 
and  reasoning,  and  each  bearing  to  the  preceding  propo- 
sitions a  consequential  or  other  close  relationship.  In 
an  exposition  of  this  carefully  built-up  type  the  trans- 
position of  a  single  section  may  send  the  whole  logical 
structure  crashing  to  the  ground  very  much  as  a  card- 
house  will  tumble  upon  the  disturbance  of  a  single  sup- 
porting card.  In  an  exposition,  then,  in  which  the  topics 
are  merely  enumerative,  the  arrangement  may  be  de- 
termined by  a  consideration  no  more  significant  than  the 
relative  importance  of  the  details  enumerated,  the  most 
important  either  being  given  precedence  over  the  others 
or  reserved  for  the  climax.     In  an  exposition  of  the  sec- 


EXPOSITION  OF  IDEAS  263 

ond  type  described  the  arrangement  will  be  determined, 
on  the  other  hand,  by  the  logical  development  of  the 
ideas,  and  is  of  the  utmost  importance  for  an  understand- 
ing of  the  whole.  Bet\/een  these  two  extremes  come 
expositions  presenting  various  problems  of  arrangement, 
the  writer  being  under  the  necessity  in  each  case  of  de- 
termining what  plan  seems  most  logical,  most  clear,  and 
most  emphatic. 

Whatever  the  specific  problem  of  arrangement  may  be, 
the  writer  should  invariably  observe  one  principle,  he 
should  plan  his  composition  as  a  whole  and  not  piece  by 
piece.  This  is  especially  necessary  in  expositions  in 
which  the  relationship  of  details  is  consequential  rather 
than  merely  sequential;  for  only  by  planning  as  a  whole 
can  the  writer  secure  real  coordination  of  details  and 
interlocking  of  parts.  In  writing  each  part  he  should 
have  in  mind  not  only  the  part  being  written  and  the 
parts  which  have  been  written  but  the  parts  to  come  as 
well,  so  that  he  may  by  anticipation  prepare  the  reader 
for  an  understanding  of  sections  lying  beyond  the  part 
being  read.  This  method  will  result  in  a  real  binding 
together  of  the  different  parts  and  will  prevent  disinte- 
gration of  the  whole  composition.  It  is  obvious  that  the 
writer  can  secure  such  coordination  only  by  carefully 
digesting  and  planning  his  material  before  he  begins  to 
write. 

Coherence  in  exposition  of  ideas  can  be  secured  then, 
especially  in  expositions  which  are  not  merely  enumera- 
tive  in  plan,  only  when  the  relationship  of  parts  is  genu- 
ine and  logical.  An  external  transition  device  will  no 
more  weld  together  two  parts  which  have  no  fundamental 
relationship  than  a  yoke  will  make  a  well-matched  team 
of  a  horse  and  an  ox.     But  if  a  logical  relationship  really 


2  64    COMPOSITION  OF  TECHNICAL  PA  PERS 

exists  between  parts,  transition  devices  of  various  sorts 
will  assist  materially  in  indicating  the  relationship  to  the 
reader.  As  the  value  of  these  "hooks  and  eyes  of  style" 
has  already  been  considered  in  Chapter  III  (see  pages 
43-44),  they  need  only  be  mentioned  here. 

Another  useful  auxiliary  device  in  assisting  the  reader 
to  follow  the  plan  of  the  exposition  of  ideas  is  the  inclu- 
sion in  the  introduction  of  a  brief  enumeration  of  the 
divisions  of  the  composition.  This  serves  the  same  pur- 
pose in  expositions  of  this  type  which  the  general  views 
of  the  whole  object  and  of  the  whole  process  do  in  tech- 
nical descriptions  and  in  process-expositions  respectively ; 
it  serves  to  provide  the  reader  with  a  chart  of  the  journey, 
so  to  speak,  with  a  view  of  the  whole  exposition  so  that 
he  is  better  able  to  relate  each  part,  as  he  reads  it, 
with  all  other  parts.  Such  an  introductory  outline 
should  not  be  regarded  as  invariably  essential,  but  in 
nine  cases  out  of  ten  its  use  will  provide  the  reader  with 
a  very  valuable  guide. 

Three  special  subjects  not  immediately  connected  with 
the  problems  of  organization  but  nevertheless  deserving 
consideration  are  the  introduction,  the  definition  of  terms, 
and  the  establishment  of  the  point  of  view  of  the  writer. 

A  satisfactory  introduction  to  an  exposition  of  ideas 
which  will  at  once  challenge  the  attention  of  the  reader 
and  escape  the  charge  of  being  a  mere  beginning  and 
nothing  more  is  not  always  easy  to  write.  Introductions 
will,  of  course,  vary  considerably,  but  they  should  always 
be  written  only  after  an  analysis  has  been  made  of  the 
relationship  of  writer  and  reader  and  of  the  particular 
demands  which  the  introductions  must  meet.  How  this 
may  be  done  will  be  shown  in  a  few  typical  cases.  Let 
it  be  supposed  that  the  exposition  is  to  be  a  definition 


EXPOSITION  OF  IDEAS  265 

or  elucidation.  One  of  the  best  ways  in  which  to  begin 
is  with  a  question  that  names  the  thing  to  be  defined  or 
states  the  problem  to  loe  solved.  The  rhetorical  ques- 
tion runs  some  risk  of  being  trite,  but  it  is  nevertheless 
often  excellent  because  it  causes  the  reader's  mind  to 
reach  out  for  the  answer  and  so  allows  the  writer  to  slip 
easily  into  his  explanation.  Or  take  the  case  of  an  expo- 
sition in  which  the  writer  demonstrates  and  defends  a 
proposition  which  is  either  new  or  at  least  different  from 
the  popular  belief.  The  best  introduction  for  such  an 
exposition  is  probably  that  which  begins  with  a  statement 
of  the  popular  belief,  for  by  beginning  thus  the  writer  is 
enabled  to  build  his  new  theory  upon  the  old,  and  some- 
times too  to  avoid  immediately  antagonizing  his  readers 
by  beginning  with  a  proposition  which  they  may  be  un- 
willing to  believe.  Excepting  in  those  comparatively 
rare  expositions  developed  inductively,  that  is,  l^  an 
array  of  evidence  leading  up  to  a  proposition  which  be- 
cause of  its  difficulty  is  withheld  to  the  end,  introductions 
should  usually  contain  a  definite  announcement  of  the 
subject,  and,  as  has  been  said  above  in  another  connec- 
tion, a  brief  enumeration  of  the  parts  of  the  exposition. 
Often  the  writer  secures  a  good  initial  contact  with  his 
reader's  mind  by  indicating  in  the  introduction  the  pur- 
pose of  the  paper  or  the  motive  which  has  prompted  him 
to  write  it,  or  by  showing  the  relation  between  his  own 
exposition  and  a  larger  subject  to  the  literature  of  which 
he  is  making  a  contribution.  These  elements  in  intro- 
ductions are  given,  of  course,  only  as  suggestions;  they 
should  not  free  the  writer  from  the  necessity  of  making 
a  close  examination  of  the  individual  problems  presented 
with  each  new  exposition. 

Failure  on  the  part  of  the  reader  to  understand  an  ex- 


266    COMPOSITION  OF  TECHNICAL  PAPERS 

position  fully  may  be  partly  the  result  of  the  writer's 
neglecting  to  explain  the  terms  which  he  uses.  This 
neglect  involves  not  only  the  failure  to  define  technical 
terms  unfamiliar  to  the  reader  but,  more  often,  to  explain 
the  writer's  interpretation  of  common  terms  which  the 
reader  may  have  a  totally  different  understanding  of. 
Without  such  an  exposition  of  the  uses  made  of  these 
terms  the  writer  may  write  with  one  set  of  ideas  in  his 
head  and  the  reader  read  with  another  set  in  his  head, 
and  the  two  may  never  get  together.  Usually  such  an 
explanation  is  made  in  the  introduction,  but  if  the  terms 
involved  are  not  used  until  well  along  in  the  paper,  defi- 
nitions of  them  had  better  be  reserved  until  needed. 

In  expositions  of  a  controversial  type  and  in  those 
which  are  heavily  charged  with  persuasion  it  is  often  im- 
portant that  the  writer  define  his  own  position  lest  the 
reader  come  to  regard  him  as  a  prejudiced  and  self- 
interested  advocate  of  the  ideas  expounded,  and  discount 
their  force  accordingly.  The  writer  should  show,  if  he 
can,  that  he  is  entirely  dispassionate  and  disinterested 
and  therefore  unbiased  in  his  judgment.  Usually  this 
demonstration  will  fit  best  into  the  introduction,  but 
sometimes  it  will  add  strength  to  the  argument  if  it  is 
put  last.  In  many  expositions  of  ideas  it  is,  moreover, 
sometimes  well  for  the  writer  to  show  modestly  but 
directly  that  he  is  in  a  position  to  speak  with  some 
authority.  If  he  indicates  briefly  the  opportunities  which 
he  has  had  to  gather  evidence  in  support  of  statements 
which  he  is  making,  he  will  run  no  risk  of  being  accused 
of  conceit,  but  will  simply  add  to  the  strength  of  his 
contentions. 


EXPOSITION  OF  IDEAS  267 

STUDENT  THEMES 

[These  themes  are  for  class  analysis.  They  are  not 
designed  to  serve  as  models.] 

I.  Causes  of  Cracking  of  Cement  Grouted  Brick  Pavements 

One  of  the  chief  difficulties  with  cement  grouted,  vitrified  brick 
pavements  is  that  such  pavements  are  subject  to  extensive  crack- 
ing. This  cracking  appears  in  three  forms,  bulges  or  upheavals 
of  the  bricks,  longitudinal  cracks,  and  transverse  cracks. 

As  might  be  expected,  the  bulges  or  upheavals  of  the  pavement 
occur  only  in  stretches  of  the  pavement  where  there  are  no  trans- 
verse expansion  joints.  Breaks  of  this  nature  occur  very  suddenly 
and  with  no  warning  whatsoever,  showing  that  the  stresses  in  the 
pavement  are  very  high.  The  reason  for  such  miniature  eruptions, 
as  they  may  properly  be  called,  is  very  simple.  When  the  pave- 
ment is  heated  up,  it  increases  in  size  and  ought  to  have  room  to 
expand  longitudinally,  as  well  as  transversely.  If  no  room  has 
been  provided  by  means  of  transverse  expansion  joints,  the  pave- 
ment is  confined  to  its  original  position  and  enormous  compressive 
stresses  are  developed.  The  result  is  that  when  the  stresses  become 
larger  than  some  portion  of  the  pavement  can  stand,  a  section  of 
the  pavement  buckles  up,  and  room  for  expansion  is  provided  in 
that  way. 

The  cause  of  the  formation  of  longitudinal ,  cracks  is  not  so 
definitely  known,  fhese  cracks  generally  occur  at  or  near  the  top 
of  the  crown  and  vary  greatly  in  length.  One  explanation  offered 
is  that  they  are  due  to  unequal  heating  of  the  surface  of  the  pave- 
ment. This  explanation  is  based  on  the  assumption  that  the  sun 
shines  on  the  centre  of  the  pavement  for  a  longer  period  of  the  day 
than  it  does  on  either  side,  and  consequently  the  variation  of  tem- 
perature is  greater  in  the  centre  than  on  the  sides.  A  much  more 
likely  reason,  however,  is  the  one  which  lays  the  trouble  to  the 
action  of  frost.  This  explanation  is  supported  by  the  facts  that 
these  cracks  always  appear  first  in  the  spring  and  that  the  founda- 
tion is  also  always  cracked.  Another  reason  for  the  formation  of 
this  type  of  crack  and  the  transverse  cracks  also  might  be  a  sub- 


268    COMPOSITION  OF  TECHNICAL  PAPERS 

grade  which  settled  in  spots  leaving  the  pavement  suspended  in  the 
air  for  a  short  time  previous  to  the  cracking. 

Aside  from  the  reason  just  mentioned  there  is  another  reason 
for  the  formation  of  transverse  cracks.  In  this  explanation  it  is 
maintained  that  a  shearing  force  perpendicular  to  the  curb  pro- 
duces the  crack.  This  shearing  force  is  set  up  by  alternate  expan- 
sion and  contraction  of  the  pavement.  To  illustrate,  we  will 
assume  a  pavement  with  plenty  of  transverse  expansion  joints  but 
with  no  soft  material  as  longitudinal  joints  between  the  curb  and  the 
brick.  When  expansion  occurs,  it  produces  forces  in  two  directions, 
parallel  and  perpendicular  to  the  curb.  The  force  parallel  to  the 
curb  tends  to  make  the  bricks  move  along  the  street,  and  the  force 
perpendicular  to  the  curb  tends  to  keep  the  bricks  from  moving  by 
increasing  the  natural  friction  between  the  bricks  and  the  curb. 
As  a  result  a  condition  obtains  which  resembles  a  cantilever  beam 
with  a  load  on  the  unsupported  end.  In  mechanics  it  is  proved 
that  such  a  condition  will  produce  a  shearing  force  parallel  to  the 
axis  of  the  beam  or  perpendicular  to  the  curb.  When  this  force 
becomes  excessive,  the  pavement  will  crack  transversely  and  relieve 
the  pressure. 

2.  Dry  Sand  and  Cement  Mixture  vs.  Mortar  Bed  for  Wood 
Block  Pavements 

In  many  of  our  cities  it  has  been  the  custom  for  many  years  to 
lay  wood  block  pavements  on  a  concrete  base,  with  a  cushion  of 
sand  or  a  bed  of  mortar  between  the  blocks  and  the  base.  To-day  it 
is  the  custom  to  put  a  mixture  of  dry  sand  and  concrete  between  the 
base  and  the  blocks.  This  latter  has  proved  much  more  successful 
than  the  former  one. 

A  sand  cushion  is  intended  primarily  to  smooth  out  the  rough- 
ness of  the  concrete  so  that  the  blocks  will  rest  evenly.  Secondly, 
the  yielding  surface  of  the  sand  permits  the  roller  to  press  the 
blocks  into  it  and  thus  to  make  an  even  surface  even  if  the  blocks 
themselves  vary  a  little  in  thickness.  Thirdly,  the  sand  has  a 
slight  resiliency  and  protects  the  blocks  from  surface  wear.  Mortar 
beds  have  a  similarity  in  that  they  act  as  an  evener  for  the  blocks. 
When  mortar  gradually  hardens,  it  loses  its  resiliency  and  takes  on 
immobility. 

There  are  two  main   objections   to   the   sand    cushion.     First, 


EXPOSITION  OF  IDEAS  269 

when  the  blocks  are  taken  up  to  make  any  repairs,  it  frequently 
happens  that  months  sometimes  elapse  before  the  repairs  are  com- 
pleted and  the  blocks  relaid;  during  this  time  rain  works  its  way 
between  the  base  and  the  blocks,  thus  disturbing  a  large  area,  which 
necessitates  the  relaying  of  all  the  damaged  portion.  This  could 
not  occur  with  either  a  mortar  bed  or  cement  bed.  Second,  the 
resiliency  of  the  sand  cushion  means  unstable  support  under  each 
block  especially  the  ends  and  sides,  which  is  of  utmost  importance 
to  the  lasting  qualities  of  the  pavement. 

The  only  objection  to  mortar  has  been  that  it  must  be  mixed 
damp,  and  time  must  be  allowed  for  the  mortar  to  set  thoroughly 
before  traffic  is  allowed  on  the  road,  whereas  a  sand  cushion  permits 
it  to  be  opened  at  once.  This  one  objection  is  now  overcome  by 
mixing  the  mortar  dry  and  allowing  the  moisture  from  the  ground 
and  air  to  set  it.  The  roller  and  immediate  travel  work  the  blocks 
down  to  the  proper  height  before  the  mortar  sets.  Work  of  this 
nature  has  been  examined  at  cuts,  and  the  bed  has  been  found 
perfect,  and  the  traffic  has  been  allowed  on  it  immediately  after  it 
was  completed. 

Another  objection  to  the  old  way  of  mixing  mortar  damp  was 
that  in  case  the  roller  broke  and  could  not  be  repaired  at  once,  all 
the  blocks  which  had  been  laid  had  to  be  torn  up  again.  The 
dry  method  overcomes  that  objection  also.  Experience  has  proved 
that  a  mortar  bed  is  far  superior  to  a  sand  bed. 

3.  Sand  and  Mortar  Cushions  for  Wood  Block  Pavements 
Wood  block  pavements  such  as  are  laid  at  the  present  time  are 
generally  made  of  the  three  following  layers:  the  concrete  base, 
the  cushion  layer  of  sand  or  mortar,  and  the  top  layer  of  creosote 
wood  blocks.  The  cushion  layer  between  the  concrete  base  and  the 
wood  blocks  serves  several  purposes,  the  greatest  one  of  which  is 
implied  by  its  name.  By  the  use  of  this  layer  it  is  also  possible 
to  obtain  a  more  smoothly  finished  surface  than  if  the  blocks  were 
laid  directly  on  the  rough  concrete  base. 

Two  different  types  of  cushion  layers  are  now  in  use,  the  one 
known  as  the  sand  cushion,  and  the  other  as  the  mortar  bed  or 
mortar  cushion.  Of  these  the  sand  cushion  was  used  earlier,  and 
up  to  about  a  year  ago  was  used  almost  exclusively.  It  is  a  layer 
of  clean,  sharp  sand  that  has  been  dampened  slightly  and  rolled 
before  the  blocks  are  laid  on  it.  It  is  generally  from  one  and  one- 
half  to  two  inches  thick,  and  for  a  short  time  after  it  has  been  laid, 


2  70    COMPOSITION  OF  TECHNICAL  PAPERS 

it  is  a  hard  cushion  to  beat.  However,  after  the  cushion  has  been 
in  place  for  some  time,  the  sand  begins  to  work  itself  up  in  the  joints 
between  the  blocks,  and  the  pavement  becomes  irregular.  Often 
this  upward  pressure  of  the  sand  in  the  joints  causes  a  large  part 
of  the  bituminous  filler  to  be  forced  out  of  the  joint  entirely,  and 
when  such  a  condition  occurs,  the  blocks  loosen  from  one  another 
and  must  be  taken  up  and  relaid. 

The  mortar  cushion  has  been  used  now  for  about  a  year  and  so 
far  has  been  giving  better  results  than  the  sand  cushion.  It  does 
not  furnish  quite  so  good  a  cushion  as  the  sand,  but  it  has  several 
advantages  that  outweigh  this  one  disadvantage.  It  is  made  of 
about  one  part  of  cement  and  four  parts  of  good  clean  sand,  all 
of  which  is  thoroughly  mixed  and  then  spread  over  the  concrete 
base  to  a  thickness  of  about  one-half  inch.  It  is  lightly  sprinkled 
with  water  just  before  the  blocks  are  placed,  which,  with  the  other 
ingredients,  makes  a  rich  mortar  of  the  layer.  This  mortar  after 
hardening  will  not  rise  up  between  the  blocks,  but  will  aid  in  hold- 
ing the  blocks  in  place. 

A  one  and  one-half  inch  sand  cushion  layer  including  the  rolling 
costs  from  six  to  nine  cents  per  square  yard,  the  amount  depending 
largely  upon  the  kind  of  sand  used  and  the  cost  of  labor.  The 
mortar  cushion  layer  in  place  and  ready  for  the  blocks  costs  from 
five  to  eight  cents  per  square  yard,  the  cost  depending  also  on 
the  kind  of  material  and  the  labor.  P'rom  these  figures  we  see 
that  the  mortar  cushion  layer  is  the  cheaper,  and  since  it  has 
proved  so  successful  during  this  last  year,  it  will,  no  doubt,  soon 
replace  the  sand  cushion  in  all  future  construction  of  wood  block 
pavements. 

4.  The  Table  of  Single  Potentials 

In  the  science  of  electrochemistry,  and  more  particularly  in 
that  branch  of  the  science  which  is  known  as  electrolysis,  there 
is  no  other  unit  of  information  which  is  so  valuable  as  the  table 
of  the  single  potentials  of  metals.  It  is  perhaps  a  little  difficult 
at  first  to  understand  just  what  is  meant  by  the  single  potential 
of  a  metal.  If  any  two  different  metals  be  dipped  into  an  elec- 
trolyte of  any  kind,  and  the  leads  of  a  voltmeter  be  attached  to  the 
two  different  metals,  then  the  voltmeter  will  register  some  value  of 
voltage,  the  magnitude  of  which  depends  upon  the  nature  of  the 
two  metals  and  of  the  electrolyte  into  which  they  dip.     In  this  case 


EXPOSITION  OF  IDEAS  271 

there  is  said  to  be  a  potential  difference  between  the  two  metals 
when  placed  in  the  electrolyte.  To  take  a  more  concrete  illustra- 
tion, if  a  plate  of  copper  and  a  plate  of  zinc  be  placed  in  an  elec- 
trolyte of  dilute  sulphuric  acid,  a  voltmeter  connected  between  the 
two  plates  will  register  approximately  1.03  volts.  Furthermore, 
it  will  be  found  that  in  the  external  circuit,  i.e.,  through  the  volt- 
meter, the  current  of  electricity  is  flowing  from  the  copper  to  the 
zinc.  This  means  that  within  the  electrolytic  cell  itself,  i.e., 
through  the  electrolyte,  the  current  is  flowing  from  the  zinc  to  the 
copper.  Because  of  this  latter  fact,  zinc  is  said  to  be  at  a  higher 
potential  than  copper. 

In  this  way  we  could  go  on  and  determine  experimentally  the 
potential  differences  between  each  metal  and  every  other  metal  in 
various  electrolytes  and  could  compile  more  or  less  useful  tables 
of  these  values  of  potential  differences.  One  can  easily  see,  how- 
ever, that  a  table  giving  the  potential  differences  between  each  metal 
and  each  of  the  other  metals  would  be  quite  long;  in  fact,  if  we  were 
to  take  only  the  twenty  most  common  metals,  there  would  be  for  a 
single  electrolyte  two  hundred  values  of  potential  differences  to  be 
experimentally  determined  and  compiled,  and  for  each  new  elec- 
trolyte there  would  be  two  hundred  more  values  to  be  laboriously 
worked  out.  To  minimize  the  amount  of  experimental  work,  and 
the  size  of  the  tables  of  potentials,  a  zero  point  of  potential  has 
been  chosen,  and  to  each  metal  has  been  assigned  a  numerical  value, 
known  as  its  "single  potential,"  which  in  reality  represents  merely 
the  potential  difference  between  this  metal  and  a  hypothetical  metal 
possessing  a  single  potential  of  zero.  From  this  it  will  be  seen  that 
the"'  zero  of  single  potentials  is  only  a  reference  point,  arbitrarily 
chosen  for  the  sake  of  convenience  alone,  and  that  it  actually  has 
no  absolute  value  in  nature.  The  scale  of  single  potentials  may  be 
compared  with  the  ordinary  Fahrenheit  thermometer  scale.  In 
this  latter  scale  the  zero  point  has  no  absolute  significance,  and  the 
expressions  "ten  above  zero,"  or  "twenty  below  zero''  merely 
define  certain  positions  in  the  whole  scale  of  temperatures.  In 
the  same  way  the  single  potential  value  which  has  been  assigned 
to  a  certain  metal  merely  defines  its  position  in  the  whole  scale  of 
potentials. 

In  the  scale  of  single  potentials  of  metals  in  chloride  solution  as 
given  below  one  can  easily  see  the  resemblance  to  the  scale  of 
temperatures. 


272    COMPOSITION  OF  TECHNICAL  PAPERS 

Magnesium 1.231  Tin —0.085 

Aluminium i.ois  Lead —0.095 

Manganese 0.824  Hydrogen -0.249 

Zinc 0.503  Bismuth —0.^15 

Cadmium 0.174  Antimony —0.376 

Iron 0.087  Arsenic —0.550 

(Hypothetical) o  .  000  Palladium -  i  .  066 

Cobalt —0.015  Platinum —  1.140 

Nickel —0.020  Gold —1-356 

This  table  has  a  number  of  uses,  which  may  be  enumerated  as 
follows : 

1.  It  shows  the  relative  stability  of  compounds  in  aqueous 
solutions;  the  higher  the  single  potential  of  the  base  metal  in  a 
compound,  the  more  stable  the  compound. 

2.  It  gives  the  voltage  that  may  be  expected  from  a  primary  cell; 
for  example,  if  a  cell  contains  the  elements  zinc  and  lead,  the  voltage 
of  the  cell  will  be  equal  to  the  algebraic  difference  between  the 
single  potential  of  zinc  and  lead.  In  this  case  the  voltage  would  be 
0.503  — (  —0.095),  which  is  equal  to  0.598  volts. 

3.  It  gives  the  direction  of  flow  of  the  current  in  such  cells;  within 
the  cell  itself,  the  direction  of  flow  will  always  be  from  the  metal  of 
higher  to  that  of  lower  potential;  externally,  of  course,  the  flow  will 
be  in  the  opposite  direction. 

4.  A  metal  of  higher  single  potential  is  able  to  precipitate  from 
a  solution  of  its  salt  any  metal  of  lower  potential. 

5.  If  two  metals  are  in  contact  and  both  are  exposed  to  corrosion, 
then  the  metal  of  higher  potential  will  corrode  first  and  will  protect 
the  other  metal.  As  an  example  of  this  may  be  cited  the  coating  of 
iron  with  zinc  to  protect  it  from  rusting. 

6.  If  two  or  more  metals  are  in  solution,  and  this  solution  is 
electrolyzed,  then  the  metals  of  lower  single  potential  will  be 
plated  out  first  by  the  current. 

There  are  a  number  of  other  uses  for  this  table,  but  to  understand 
such  uses  one  will  require  a  much  broader  knowledge  of  the  science 
of  electrochemistry  than  can  be  covered  in  this  brief  paper. 

5.  The  Solution  of  Problems^ 

In  order  to  obtain  the  solution  of  any  specific  problem  various 
methods  may  be  applied,  but  experience  has  shown  that  there  are 
1  Compare  Suggestions  on  the  Study  of  Mathematics,  p.  216. 


EXPOSITION  OF  IDEAS  273 

usually  only  a  few  good  methods  which  will  work  out  satisfactorily, 
and  innumerable  bad  ones  which  will  not.  No  matter  whether 
arithmetical,  algebraical,  geometrical,  graphical,  calculus,  or  hybrid 
methods  of  solution  be  used,  there  are  nevertheless  certain  factors 
which  produce  faulty  and  inaccurate  results  and  others  that  result 
in  accuracy  and  logical  processes  of  thought.  I  shall  explain  in 
this  paper  merely  what  the  difficulties  are. 

Among  the  difficulties  encountered  in  the  solution  of  problems  and 
the  causes  of  poor  results  are:  the  initial  difficulty  of  choosing  the 
correct  method  of  attack,  confusion  in  handling  unknown  quantities, 
lack  of  neatness  and  lack  of  care  in  each  step  of  the  process,  and 
losing  the  train  of  thought. 

It  is  often  a  difficult  matter  to  decide  upon  the  method  of  solu- 
tion of  a  specific  problem.  One  reason  to  account  for  this  is  that 
the  person  who  is  attempting  to  solve  the  problem  very  often 
imagines  that  it  is  necessary  for  him  to  see  the  method  of  solution 
in  its  entirety  before  he  can  proceed  with  the  numerical  computa- 
tions, and  as  a  result  he  usually  never  gets  started.  The  other 
extreme  is  that  of  a  person  who  blindly  tackles  a  problem  without 
preliminary  thought  or  consideration.  His  fault  is  that  of  mis- 
guided energy  whereas  the  other  man's  is  that  of  lack  of  initiative. 
Even  though  both  of  these  methods  enable  one  to  solve  very  many 
problems,  yet  the  man  who  uses  them  does  not  derive  the  mental 
development  that  he  would  receive  by  adopting  more  logical 
methods.  Perhaps  the  most  common  short-coming  of  all  is  that  of 
solving  problems  by  means  of  fixed  types,  formulas,  or  examples, 
without  an  understanding  of  the  significance  of  the  terms  involved. 
This  is  a  machine-like  method  of  grinding  out  solutions  and  should 
by  all  means  be  avoided. 

Unknown  quantities  in  a  solution  tend  to  cause  confusion  because 
it  is  then  necessary  to  hunt  up  sufficient  equations  to  enable  one  to 
obtain  the  desired  unknown.  At  first  sight  it  appears  that  insuffi- 
cient data  have  been  given,  and  for  that  reason  one  is  often  bewild- 
ered. -The  difficulty  in  handling  unknowns  is  due  to  the  fact 
that  they  must  be  represented  by  certain  expressions  which  depend 
upon  the  conditions  in  the  problem,  and  must  be  treated  throughout 
the  solution  as  though  they  were  constants. 

Lack  of  neatness  causes  many  a  problem  failure  either  by  intro- 
ducing small  errors  or  by  veiling  the  method  of  procedure.  If  a 
man  does  not  take  pains  to  be  neat  while  working  a  problem,  he 


274    COMPOSITION  OF  TECHNICAL  PAPERS 

then  has  a  marked  tendency  toward  making  slight  mistakes  such  as 
misplacing  the  decimal  point,  making  illegible  figures,  or  running 
all  the  steps  in  the  process  into  one  confused  mess.  In  case  a  prob- 
lem is  long  and  complicated,  it  is  seen  that  he  might  desire  to 
refer  back  to  the  first  portion  of  the  solution  from  time  to  time  in 
order  to  follow  a  logical  method  of  procedure.  Consequently,  if 
his  work  has  been  put  down  in  poor  shape,  he  will  find  it  diflficult  to 
refresh  his  memory  by  such  a  review  and  may  even  lose  the  train  of 
thought  which  was  followed  in  the  first  portion  of  his  solution. 

If  a  definite  train  of  thought  from  start  to  finish  of  a  problem  is 
not  carried  out,  innumerable  working  hypotheses  crowd  upon  the 
mind  and  produce  confusion.  For  this  reason  it  is  better  to  follow 
out  an  incorrect  method  to  the  finish,  unless  one  is  assured  as  to  its 
incorrectness  before  the  final  stage  is  reached,  than  it  is  to  start  out 
with  the  correct  hypothesis  and  then  drift  into  others  which, 
although  correct  in  themselves,  do  not  combine  with  the  initial 
one. 

6.  The  Chemical  Engineer 

As  the  field  of  chemical  engineering  is  comparatively  new  and 
consequently  unknown,  the  prospective  chemical  engineer  is  very 
often  called  upon  to  define  exactly  the  line  of  work  for  which  his 
course  is  preparing  him.  And  just  as  often  he  will  have  to  hesitate 
before  making  his  reply.  Although  this  would  seem  to  indicate 
that  the  field  of  chemical  engineering  is  an  indefinite  thing,  and 
that  its  followers  are  blind  wanderers  along  an  unknown  path,  this 
is  not  the  case.  It  is  only  because  he  perceives  the  tremendous 
scope  of  his  chosen  work,  and  because  he  realizes  his  inability  to 
define  its  limits  closely,  that  the  chemical  engineering  student  has 
to  stop  and  ponder  before  giving  his  answer.  He  knows  that,  upon 
leaving  college,  he  will  be  able  to  fill  competently  any  one  of  a 
number  of  dififerent  positions,  but  to  explain  that  possibility  to 
the  layman  in  a  few  comprehensive  sentences  is  to  him  a  difficult 
matter. 

It  has  been  said  that  the  chemical  engineer  is  an  industrial 
chemist.  To  a  certain  extent  that  is  true,  but  as  a  definition  the 
statement  is  too  limiting.  Not  only  is  the  chemical  engineer  the 
link  between  the  theoretical  chemist's  laboratory  and  the  practical 
business  man's  workshop,  but  he  is  also  an  efficiency  engineer, 


EXPOSITION  OF  IDEAS  275 

always  on  the  watch  for  a  way  in  which  to  simplify  a  process,  cut 
down  a  cost,  or  make  use  of  a  hitherto  useless  by-product.  He  has 
been  trained  not  only  to  know  that  A  added  to  B  will  produce  C, 
but  also  to  realize  that  such  an  operation  will  cost  a  certain  number 
of  dollars  and  cents,  which  the  market  value  of  C  must  recover. 
And,  while  the  chemist  is  viewing  everything  from  the  laboratory 
standpoint,  the  chemical  engineer  thinks  on  a  commercial  scale, 
realizing  that,  in  the  transition  from  the  laboratory  to  the  factory, 
difi&culties  will  arise  to  threaten  the  success  of  a  process  which  in 
the  laboratory  may  have  seemed  to  have  been  well  planned. 

It  is  therefore  necessary  not  only  that  the  chemical  engineer 
should  be  well  grounded  in  all  branches  of  chemistry,  but  that  he 
should  also  have  a  working  knowledge  of  the  fundamentals  of 
mechanical,  civil,  and  electrical  engineering.  And  to  round  him 
out  for  contact  with  business  life  he  must  be  conversant  with  the 
principles  of  economics  and  commercial  law.  He  may  be  said  to  be 
a  sort  of  engineering  jack-of-all-trades,  but,  while  master  of  none, 
he  is  beginning  to  combine  them  all  into  one,  the  knowledge  of 
which  is  making  him  indispensable  in  practically  every  creative 
industry.  In  brief,  the  chemical  engineer  is  a  by-product  of  our 
modern  industrial  development  and  the  direct  result  of  an  attempt 
to  produce  a  highly  trained  technical  man  who  has  not  been  nar- 
rowed by  specialization,  but  who  has  been  broadened  in  spite  of  it. 

7.  The  Business  Man  and  the  College  Man 

The  business  man  who  has  neyer  had  a  college  training  is  apt  to 
look  upon  the  college  man  as  a  "smarty"  who  knows  next  to 
nothing.  Indeed,  this  is  very  often  the  case  with  this  kind  of  busi- 
ness man.  This  attitude  is  very  hard  to  explain  because  in  most 
cases  it  has  no  solid  foundation.  If  you  should  ask  such  a  man  why 
he  harbors  this  feeling,  he  would  probably  say  that  the  college 
man  thinks  that  no  one  but  he  knows  anything.  Of  course,  this 
may  be  true  of  a  few  college  men,  but  the  vast  majority,  I  am  sure, 
are  broad-minded  enough  not  to  think  this  or  even  to  show  any 
tendencies  in  this  way.  I  think  that  this  business  man  is  usually 
the  one  who  has  worked  himself  up  to  his  position  or  in  other  words 
claims  to  be  a  self-made  man.  He  does  not  see  that  it  is  the  college 
man  who  is  becoming  more  and  more  the  leader  in  all  things  and  the 
one  who  sets  the  pace  of  civilization.     This  hard  feeling  is  indeed 


276    COMPOSITION  OF  TECHNICAL  PAPERS 

deplorable  and  may  be  said  to  be  slowly  dying  out  because  the 
self-made  man,  the  man  without  an  education,  is  becoming  scarcer 
than  in  former  years.  If  this  type  of  man  could  be  brought  into 
close  touch  with  the  college  man,  it  would  no  doubt  benefit  both. 
It  would  broaden  the  viewpoint  of  the  business  man  and  give  the 
college  man  the  views  of  the  self-made  man. 

There  is  still  another  type  of  business  man,  the  one  who  has  had 
an  education  or  who  at  least  recognizes  its  value.  Between  this 
man  and  the  college  man  are  found  the  closest  sympathies.  These 
two  understand  each  other,  and  they  both  realize  each  other's 
importance.  This  kind  of  business  man  is  the  one  who  makes  the 
college  a  success  and  spurs  on  the  average  man  to  acquire  an  educa- 
tion. He  is  the  one  that  sets  the  aim  of  the  college  man  and 
gives  him  inspiration  for  his  work.  He  is  the  one  who  sees  the 
necessity  for  college  training  and  sees  the  benefits  derived  from  it. 
Still  there  is  a  lot  to  be  done  to  improve  the  relations  between  the 
business  man  and  the  college  man.  For  example,  the  college  man 
does  not  very  often  appreciate  the  fact  that  he,  like  every  one  else, 
must  begin  at  the  bottom  and  work  up  to  the  top.  He  thinks  that 
he  is  entitled  to  a  big  position  just  because  he  has  an  education. 
The  college  man  is  apt  to  hold  his  not  getting  a  big  position  against 
the  business  man.  But  then  again  this  is  also  fast  being  stamped 
out  of  his  mind  through  the  efforts  of  instructors  and  business 
men,  and  he  is  beginning  to  realize  the  justice  of  the  business  man's 
ways. 

8.  The  Value  of  Technical  Jotjrnalistic  Work  to  the  Engi- 
neering Student 

Every  student  in  the  university  is  at  some  time  confronted  with 
the  question  of  the  advisability  of  entering  some  extra-curricular 
activity.  Student  tradition  demands  that  a  man  do  something 
to  distinguish  himself  outside  the  class-room.  As  a  result,  to  some 
extent,  of  this  tradition,  almost  unlimited  opportunities  for  such 
activities  afford  themselves  in  the  student  commonwealth.  The 
engineer,  if  he  be  honest,  cannot  plead  guilty  of  lack  of  time  for 
such  things,  for,  stiff  as  his  course  may  be,  he  invariably  has  some 
time  in  which  he  has  no  definite  work  to  do.  The  question  arises, 
then,  as  to  which  direction  the  engineer's  activities  should  lead  him, 
and  it  would  seem  that  one  of  the  best  answers  is  found  in  technical 
journalism. 


EXPOSITION  OF  IDEAS  277 

Journalism  is  one  of  the  greatest  of  all  schools  of  experience. 
This  holds  equally  true  for  both  the  editorial  and  business  depart- 
ments of  the  work.  It  need  not  be  proved  by  any  lengthy  dis- 
cussion that  the  experience  to  be  gained  on  a  technical  magazine 
is  especially  valuable  to  men  equipping  themselves  with  a  technical 
education.  But  some  of  the  more  immediate  benefits  that  are 
outstanding  may  be  mentioned  in  passing.  For  the  technical 
student  leaning  toward  the  commercial  phases  of  his  work  there  is 
no  better  experience  to  be  gained  from  college  life  than  to  solicit 
advertising  from  firms  who  consider  such  advertising  outright 
charity,  a  task  worthy  of  comparison  with  that  of  the  advertising 
manager  of  any  non-student  publication.  The  handling  of  such  a 
small  enterprise  on  very  close  margins  and  with  perhaps  little  re- 
sponsibility is  a  real  test  of  a  man's  economy,  foresight,  ingenuity, 
and  strict  integrity,  which  is  something  more  than  mere  rhetorical 
integrity. 

For  the  technical  student  interested  in  writing  the  real  experi- 
ence of  obtaining  the  right  material  at  the  right  time  from  the  right 
man, — a  problem  in  keenness  of  observation, — of  editing  that 
material  in  the  right  way  in  order  to  give  it  its  best  appearance 
without  destroying  too  much  of  the  author's  original  form,  of 
getting  that  material  printed  in  the  right  way  in  order  to  draw  its 
proper  share  of  attention, — such  experience  is  to  be  found  just  as 
well  in  the  student  as  in  the  non-student  publication.  The  smaller 
details  of  the  work  round  out  that  experience  to  a  full  fruitage. 

It  is  of  especial  value  to  a  man  to  carry  a  certain  share  of  fixed 
responsibility  and  to  carry  it  without  tangible  recompense.  In 
the  little  share  of  glory  that  a  man  gets  from  a  year's  work  on  the 
staff  of  a  student  publication  there  is  little  of  the  wherewithal  on 
which  to  live  from  board  bill  to  board  bill.  It  is  comparatively 
easy  to  do  an  assigned  amount  of  work  when  there  is  a  pay  envelope 
to  follow  at  the  end  of  the  week,  but  when  the  stimulus  has  to  be 
the  joy  of  working,  the  work  does  not  progress  so  smoothly. 

There  is  one  thing  to  be  gained  from  work  on  such  a  magazine 
which  is  often  misinterpreted  by  some  persons.  It  follows  naturally 
in  a  school  where  the  faculty  are  interested  in  the  school  publication 
that  the  students  working  on  the  publication  are  brought  more  or 
less  under  the  attention  of  the  faculty  men.  The  chronic  cynics 
brand  this  type  of  activity,  therefore,  as  "working  for  a  stand-in." 
No  faculty  man  can  be  blamed  for  failing  to  recognize  a  man's 
18 


278   COMPOSITION  OF  TECHNICAL  PAPERS 

merits  if  he  willfully  hides  himself  in  the  crowd.  Nor  can  any 
student  be  blamed  for  trying  to  raise  his  head  just  a  trifle  above 
those  around  him  so  that  the  instructor  may  at  least  recognize 
him  as  an  individual  in  the  crowd.  This  does  not  foreshadow  a 
phenomenal  rise  in  the  standings  of  that  student.  The  results 
seldom  show  during  a  man's  college  course.  But  the  time  will 
come,  perhaps  at  graduation,  perhaps  some  years  later,  when  the 
mere  fact  that  the  man's  head  was  raised  just  a  trifle  higher  than 
those  about  him  will  throw  the  balance  of  influence  in  his  favor. 
And  thus  the  work  is,  even  in  this  respect,  an  excellent  preparation 
or  the  long  years  after  commencement. 


EXPOSITION  OF  IDEAS  279 

EXPOSITIONS  OF  IDEAS 

Electric  Heating  Devices^ 

John  F.  Robertson 

[A  frequent  type  of  technical  exposition  is  the  letter  to 
the  editor  of  a  technical  magazine  from  a  writer  who 
wishes  to  comment  briefly  and  informally  upon  some 
matter  which  he  believes  worth  the  notice  of  the  readers. 
Such  a  letter,  on  a  commercial  aspect  of  the  profession, 
follows.  It  is  suggested  that  a  profitable  theme  would 
be  the  writing  of  a  letter  to  the  editor  of  the  college  or 
other  engineering  magazine.] 

To  the  Editors  of  Electrical  World: 

Sirs: — It  is  strangely  singular,  though  by  no  means  inexplicable, 
how  central-station  managers,  and  solicitors  in  particular,  will 
induce  a  consumer  to  load  up  his  circuits  with  almost  every  con- 
ceivable form  of  electric-heating  device  without  any  thought  as 
to  the  ability  of  the  consumer  to  keep  such  apparatus  in  operation. 
Seldom — and  this  point  has  been  emphasized  often — does  the 
manager  or  solicitor  stop  to  ask  himself  whether  the  consumer's 
income  is  such  as  to  warrant  the  installation  of  certain  heating 
devices,  especially  if  the  energy  is  not  sold  at  very  low  rates.  It  is 
generally  admitted  that  unless  low  rates  for  heating  circuits  prevail, 
it  is  out  of  the  question  for  an  average  clerk  to  roast  meats  in  an 
electric  oven  in  competition  with  other  fuel,  unless,  of  course,  there 
are  very  urgent  reasons  for  using  electricity. 

The  average  solicitor,  if  he  felt  that  a  consumer  would  take  his 
advice,  would  suggest  that  the  entire  house  be  electrically  equipped, 
and  could  frame  up  enough  arguments  to  convince  an  easily-led 
individual  that  that  would  be  the  proper  thing  to  do.  This  is  not 
only  detrimental  to  the  central  station  and  to  the  manufacturer 
of  heating  devices,  but  to  the  whole  art  as  well.     Even  customers 

»  Reprinted  from  the  Electrical  World  by  permission  of  the  publishers. 


28o    COMPOSITION  OF  TECHNICAL  PAPERS 

who  can  afford  to  pay  high  rates  in  return  for  the  cleanliness  and 
convenience  of  electricity,  have  installed  cooking  and  heating  appa- 
ratus often  at  great  expense,  and  discarded  it  again  after  a  short 
period  of  use.  Granting  that  the  apparatus  itself  is  thoroughly 
reliable,  it  is  but  right  that  a  consumer  be  apprised  of  all  the  facts 
in  connection  with  it.  The  luminous  radiator,  for  instance,  is  a 
very  pretty  piece  of  apparatus;  but  as  an  economical  heat  producer 
it  is  an  admitted  failure,  and  for  a  manager  to  push  apparatus  of 
this  kind  without  stating  that  it  is  especially  serviceable  for  bath- 
rooms, sitting-rooms,  etc.,  where  heat  is  required  for  short  periods 
of  time  only  or  to  take  the  chill  off  the  room,  only  tends  to  bring 
discredit  and  to  hinder  the  legitimate  development  of  the  business 
in  other  directions.  Unless  a  man  has  a  fairly  large  income,  can 
he  afford  to  place  electric  cooking  utensils  in  the  hand  of  the  average 
cook  in  a  family  of  more  than  five,  for  instance?  In  the  first  place, 
the  cost  of  some  kettles  is  such  that  it  would  be  possible  for  the 
same  sum  to  buy  a  whole  outfit  of  ordinary  cooking  utensils. 
Renewals  are  also  costly,  and  if  the  manufacturers  of  heating  appa- 
ratus would  make  heating  elements  in  sections  and  make  them  as 
readily  replaceable  as  fuses  in  a  circuit,  for  example,  progress  will 
be  made. 

There  are  numerous  devices  on  the  market  which  are  very 
serviceable  and  which  come  within  the  means  of  even  the  poorest, 
or  at  least  anyone  having  electricity  in  his  dwelling.  The  first 
cost  is  usually  the  only  hindrance  to  their  introduction,  and  if 
central  stations  would  rent  these  as  they  do  flat-irons,  etc.,  on  a 
basis  commensurable  with  their  convenience,  the  general  public 
will  be  likely  to  entertain  the  suggestion  of  the  most  persuasive 
and  eloquent  canvassers  employed.  There  is  no  doubt  a  field  for 
extensive  operations  in  this  direction  if  approached  in  the  proper 
manner.  Thaf  manner  is  certainly  not  to  try  to  bankrupt  a  con- 
sumer by  installing  apparatus  consuming  more  energy  than  he  is 
able  to  buy. 

A  manager  may  as  well  be  frank  with  a  patron  of  his  company, 
and  if  in  his  estimation  it  would  be  detrimental  to  the  interests 
of  a  customer  to  install  certain  apparatus,  although  seemingly 
advantageous  to  the  electric-light  company  at  first,  it  would  be 
wise  for  him  so  to  advise  the  customer.  Such  frankness  and  solici- 
tude always  bring  their  reward. 

New  York.  John  F.  Robertson. 


EXPOSITION  OF  IDEAS  281 

How  TO  Use  the  Technical  Journal ^ 

Paper  (Slightly  Condensed)  by  John  W.  Alvord,  Con- 
sulting Engineer,  of  Chicago,  Presented  at  the  Conven- 
tion of  the  Federation  of  Trade  Press  Associations,  Chi- 
cago, September  24-26. 

[The  following  article  is  reprinted  partly  because  it 
affords  a  good  illustration  of  expository  analysis  and 
classification  and  partly  because  of  its  relation  to  the 
general  subject  of  writing  and  reading  engineering  arti- 
cles. It  is  suggested  that  it  be  used  as  the  basis  for  a 
class  discussion  of  the  value  and  use  of  the  engineering 
journal  and  for  a  theme  on  How  I  Read  My  Engineering 
Journal,  The  Make-up  of  My  Engineering  Journal,  Why 
I  Like  the {name  of  technical  journal) ,  Some  Sug- 
gestions for  Indexing  and  Clipping  Engineering  Journals, 
or  some  similar  subject  designed  to  stimulate  interest  in 
the  important  matters  of  reading  intelligently  and  pre- 
serving information  economically.  The  brief  editorial 
comment  on  Mr.  Alvord's  paper  was  taken  from  the 
Engineering  Record  of  the  same  date  and  is  here  repro- 
duced with  the  thought  that  it  might  add  interest  to  the 
reading  of  the  main  article.] 

In  1880,  when  the  writer  first  commenced  to  take  some  interest 
in  technical  journals,  such  publications  in  this  country  were  rela- 
tively few.  We  had  the  Engineering  News  (1874),  the  Sanitary 
Engineer  and  Building  Record  (1880)  (now  the  Engineering  Record) 
Van  Nostrand's  Magazine  (now  defunct),  the  American  Engineer 
and  Railway  Journal  (1832),  the  Railway  and  Engineering  Review 
(1864),  Railway  Age  Gazette  (1856),  the  Engineering  and  Mining^ 
Journal  (1866),  the  Electrical  World  (1874),  and  a  number  of 
trade    papers  of  some  interest  to  engineers.     Only  the   railway 

1  Reprinted  from  the  Engineering  Record  for  October  3,  1914.  by  permis- 
sion of  the  publishers.  The  condensing  was  done  by  the  publishers  from 
the  original  paper. 


282    COMPOSITION  OF  TECHNICAL  PAPERS 

journals  were  really  financially  able  to  cover  the  ground  in 
their  respective  fields.  All  were  far  less  comprehensive  than 
at  present.  In  1880,  the  engineer  treasured  and  indexed  al- 
most every  scrap  of  printed  matter  on  any  engineering  subject 
that  came  his  way.  To-day  his  task  is  to  sort  out,  discard,  and 
eliminate  that  which  he  can  no  longer  use,  and  limit  himself  to  the 
inspection  and  reading  of  that  which  bears  principally  on  his 
selected  professional  specialty. 

That  we  cannot  keep  abreast  of  the  times  without  reading  the 
engineering  journals  is  obvious.  That  if  we  carefully  read  all 
the  engineering  journals  in  our  chosen  specialty  we  would  have  no 
time  left  to  earn  a  living  is  easily  capable  of  demonstration.  What 
then  is  the  proper  attitude  to  adopt  toward  this  ever-increasing 
flood  of  information  that  pours  in  upon  us  so  relentlessly? 

Subscribers'  Attitude  towari>  Paper 

If  we  look  about  us  to  see  how  our  fellow  engineers  solve  this 
matter  we  shall  find  a  great  variety  of  attitudes  toward  the  problem. 
Some  engineers  simply  do  not  take  engineering  journals,  reading 
one  occasionally  here  and  there  as  opportunity  ofliers.  Others 
take  all  they  can  afford  to  take  and  let  them  pile  up  around  the 
oflSce,  often  unopened  and  unused.  Others  still  limit  themselves 
to  a  select  few,  which  they  carefully  bind  and  shelve.  Still  others 
read  journals  when  they  can,  and  throw  them  away  when  they 
move  on.  As  a  rule,  however,  the  engineer  prizes  his  technical 
paper,  and  endeavors  in  some  ill-defined  and  formless  sort  of  fashion 
to  preserve  its  information  for  future  use.  Generally  he  fails  to 
find  any  practicable  scheme  which  makes  his  rapidly  accumulating 
material  of  much  value  to  him  after  it  has  once  passed  under  his 
eye,  and  for  a  large  number  of  engineers,  technical  journals  are  only 
professional  newspapers  with  which  to  idle  away  an  hour  or  so  and 
satisfy  their  curiosity.  That  their  value  is  something  much  more 
than  this,  or  should  be  more  than  this,  is  so  apparent  as  to  need  no 
denial. 

The  problem  of  the  engineer  with  his  technical  paper  is  much 
affected  by  his  age,  station  and  aim  in  life.  To  the  man  who  is  in 
engineering  only  to  get  money  and  more  money,  the  engineering 
journal  is  a  newspaper,  in  which  he  may  notice  mainly  where  there 


EXPOSITION  OF  IDEAS  283 

are  better  jobs  than  his  own  that  may  be  sought  after  and  perhaps 
obtained.  To  the  man  who  is  anxious  to  fit  himself  every  year  of 
his  life  for  something  better  it  is  an  opportunity,  quite  unequaled 
many  years  ago,  for  a  great  variety  of  study.  To  the  young 
engineer  the  engineering  journal,  properly  read  and  noted,  is  a 
part  of  a  post-graduate  course  in  engineering.  To  the  middle-aged 
man  it  is  a  mine  of  data,  bearing  in  all  sorts  of  ways  on  his  work;  and 
to  the  mature  specialist  only  does  it  begin  to  become  burdensome 
by  its  repetition  of  experience,  and  its  volume  of  matter  on  subject 
which  has  already,  to  him  at  least,  been  well  digested.  Let  us  see 
if  we  can  outline  how  each  of  these  classes  can  get  more  profit  out 
of  the  matter  contained  in  the  engineering  journals  than  do  the 
careless  or  the  indifferent,  who,  after  their  journal  is  once  looked 
over,  let  it  go  to  waste  or  idleness. 

Problem  of  Young  Engineer 

The  young  engineer  and  the  college  graduate  need,  most  of  all, 
practical  experience.  It  is  safe  to  say  that  engineering  literature 
will  never  have  any  proper  perspective  for  him  until  he  has  been 
connected  in  some  capacity  with  engineering  work  himself,  be  it  in 
ever  so  modest  a  capacity.  With  the  actual  doing  of  engineering 
work,  however,  should  come  contemporaneously  the  reading  of 
technical  journals,  particularly  along  the  lines  in  which  he  is  work- 
ing. Nothing  can  be  more  instructive,  broadening,  and  enlighten- 
ing to  a  man  doing  a  particular  kind  of  work  than  reading  about 
similar  work  at  the  same  time.  It  follows,  therefore,  that  the 
young  engineer  should  as  early  as  possible,  take  at  least  one  first- 
class  engineering  journal  and  own  it  himself;  bind  it  if  he  can  afford 
to,  but  lay  it  away  in  an  orderly  manner,  in  any  event.  If  he  can 
afford  two  journals  so  much  the  better,  especially  if  they  are  selected 
so  as  to  widen  his  outlook. 

It  is  to  be  doubted  if  laborious  reading  of  all  kinds  of  engineering 
articles  all  the  time  is  advisable  for  anyone.  Mere  quantity  of 
reading  is  mentally  detrimental.  If  one  might  advise,  it  would  be 
to  suggest  enforced  systematic  reading  of  all  articles  particularly 
bearing  on  the  line  of  work  the  reader  is  immediately  engaged  upon, 
and  the  optional  reading  only  of  such  other  articles  as  interest  him. 
This  ought  not  to  be  much  of  a  task.     In  course  of  time  as  his 


284    COMPOSITION  OF  TECHNICAL  PAPERS 

experience  broadens,  engineering  reading  will  become  less  burden- 
some and  more  interesting  because  its  relation  to  practical  matters 
will  be  more  and  more  appreciated,  and  the  discriminating  use  of 
engineering  literature  better  understood.  Of  course,  all  this  applies 
to  engineering  societies  as  well;  but  that  is  another  story. 


Card  Index  Caution 

It  is  probably  not  wise  for  the  young  engineer  to  indulge  exten- 
sively in  card  indexes,  filing  systems,  and  the  like,  for  topically 
arranging  his  available  engineering  journal  articles.  Few  men 
know  very  early  in  life  where  fate  and  interest  will  land  their  future 
attention,  and  filing  systems  and  special  indexes  are  expensive  and 
time  consuming,  and  when  indulged  in  without  definite  aim  nearly 
always  quickly  become  too  voluminous  and  thereby  useless.  If 
any  suggestions  are  made  along  this  line,  it  would  be  to  start  a 
loose  leaf,  letter-size  (83'^  X  ii-in.  page)  notebook  and  note  in  it 
(separate  pages  for  separate  subjects)  only  what  appears  to  be 
extremely  useful,  either  in  exceedingly  brief  abstracts  from  engi- 
neering articles,  or  diagrams,  costs,  etc. 

The  young  engineer  is  tempted  to  read  much  about  large  enter- 
prises— the  Panama  Canal,  big  bridges,  astonishing  tunnels,  great 
dams.  This  does  no  harm,  and  probably  holds  his  interest  for  the 
time  being.  Gradually  he  learns  that,  for  him  at  least,  the  chief 
value  of  the  technical  journal  does  not  lie  in  its  dramatic  side, 
necessary  as  that  may  be  for  our  general  information,  interest 
and  pleasure,  but  its  chief  value  lies  in  a  fund  of  small  things,  which 
make  up  routine  work  of  the  ordinary  every-day  job.  These 
are  to  be  watched  for,  and  noted,  as  practically  useful  to  the  average 
man. 

The  Middle-aged  Reader 

We  next  come  to  the  man  in  early  middle  life,  actively  engaged 
in  his  profession,  and  note  at  once  that  his  problem  with  the 
technical  journal  is  the  absence  of  "time."  Absorbed  in  a  mul- 
titude of  responsibilities,  harassed  with  unexpected  difficulties, 
worn  out  at  night  with  the  long  day  of  strain,  how  shall  he  derive 
any  useful  good  from  the  multitude  of  journals  which  his  more 
ample  income  can  readily  afford,  but  which  pile  high  on  his  table 


EXPOSITION  OF  IDEAS  285 

after  every  brief  absence  from  the  office?  Whether  or  not  such  an 
engineer  shall  make  any  eflfort  to  systematically  assimilate,  file, 
and  study  current  technical  journals  depends  in  part  upon  the 
nature  of  his  routine.  If  he  is  largely  engaged  in  administrative 
work,  or  is  a  salaried  officer  in  a  large  enterprise  with  a  compara- 
tively limited  range  of  problem  or  a  limited  call  for  miscellaneous 
data,  he  may  generally  be  content  with  a  cursory  examination  of 
the  engineering  journal  such  as  will  keep  him  qualified  on  his  under- 
taking, and  the  preservation  of  such  journals  in  bound  form,  with 
the  standard  published  indexes.  If,  however,  he  is  entering  upon 
novel  work,  or  work  presenting  a  great  variety  of  problems,  over- 
lapping into  a  great  variety  of  fields,  ambition  will  compel  him  to 
do  more  than  this,  and  some  form  of  special  indexing  will  appeal 
to  him  more  or  less  strongly  as  he  feels  the  need  more  often  for 
research  in  up-do-date  material. 

The  average  editor  can  judge  of  a  technical  article  with  only  a 
brief  inspection — a  sentence  here  and  there,  a  headline,  and  a 
moment's  reading  of  the  summary  and  conclusion.  Long  fami- 
liarity with  matter  of  a  similar  character  gives  him  the  assurance 
that  he  can  detect  in  this  rapid  review  anything  novel,  new,  or 
original,  and  can  fairly  pass  judgment  upon  it  in  a  general  way. 
The  working  engineer  who  has  had  some  experience  with  technical 
literature  can  form  the  same  habit,  and  save  much  time.  It  is 
really  wonderful  how  much  repetition  there  is  in  engineering  writing 
and  in  the  production  of  engineering  papers.  It  thus  happens  that 
we  are  under  the  necessity  of  seeing  much  the  same  facts  and 
principles  repeatedly  published  in  varying  form,  for  some  one  is 
always  attracted  to  really  read  them,  with  consequent  benefit  to 
himself,  under  the  belief  that  they  are  new  and  novel. 

The  mature  engineer  notes  that  a  large  amount  of  engineering 
literature  is  of  the  purely  descriptive  order,  merely  giving  out- 
line of  work  that  has  been  accomplished,  without  going  into  reasons 
or  principles.  All  this  kind  of  writing  is  valuable  and  useful,  and 
has  its  proper  place,  but  all  of  this  class  of  literature  has  its  limita- 
tions. One  of  the  most  severe  of  its  limitations  is  that  it  rarely 
describes  mistakes,  errors  of  judgment,  or  failures,  and  in  these  lie 
the  most  valuable  lessons  to  the  seeker  after  truth.  One  is  obliged 
to  read  between  the  lines  or  read  with  reservation,  much  as  one  does 
in  reading  accounts  of  battles  in  the  daily  press.  It  is  always  wise 
to  look  back  and  note  the  origin  of  the  despatches  in  such  cases. 


286    COMPOSITION  OF  TECHNICAL  PAPERS 

A  tremendous  lot  of  engineering  literature  is  written  which  is 
of  little  permanent  value.  Often  it  represents  the  writer's  struggles 
to  understand  a  subject.  Often  it  is  compiled  largely  from  a 
desire  for  publicity.  Fortunately  the  editors  of  the  technical 
papers  can  limit  this  kind  of  reading  by  care  in  selection. 

Separating  Wheat  from  Chaff 

But  amid  all  these  drawbacks  a  discriminating  mind  will  always 
find  a  great  deal  of  wheat  amid  the  chaff,  and  the  wheat  that  will 
be  gleaned  will  be  of  differing  kind  and  amount,  depending  upon  the 
type  of  mind  of  the  reader,  his  present  problem,  and  his  desire  to 
systematize  his  information.  What,  therefore,  shall  he  do  with  his 
special  selection  when  once  he  thinks  he  has  separated  it  from  the 
flood  of  raw  material? 

Several  courses  are  open  to  him : 

First,  he  may  rely  on  his  memory  and  the  published  index  to  his 
bound  volumes.  It  is  safe  to  say,  however,  that  few  engineers 
really  make  much  practical  use  of  this  method.  The  intervening 
index  and  the  bother  of  a  search  prove  to  be  discouraging  to  that 
degree  that  a  proposed  reference  search  is  abandoned  in  about  one- 
half  the  suggested  attempts.  The  ideal  filing  system  is  one  in 
which,  with  the  least  amount  of  effort,  one  can  put  his  hand  im- 
mediately and  accurately  on  the  thing  itself,  be  it  a  book,  a  pamph- 
let, or  a  data  sheet. 

Second,  he  may  keep  a  special  card' index  of  important  data  and 
reference  to  valuable  articles.  This  at  once  involves  labor  and 
attention  which  few  busy  men  can  give  and  which,  if  done  by  assist- 
ants or  librarians,  largely  loses  its  personal  value  to  the  one  who 
needs  it.  The  same  objection  as  to  the  discouraging  effect  of  in- 
tervening indexes  holds  good  here,  too,  and  it  is  further  safe  to 
say  that  of  all  the  contrivances  for  indexing  the  most  difficult  to 
handle  readily  and  examine  rapidly  is  the  card  index  system. 

Third,  he  may  abstract  important  data  in  a  limited  way  on 
loose  leaf  transparent  paper,  standard  letter-size,  and  he  may  re- 
move or  detach  articles  of  special  value  from  out  his  journals,  to 
be  filed  in  regular  office  file  system,  like  correspondence. 

The  writer  has  tried  all  of  the  above  methods  at  considerable 
cost  in  time  and  patience,  and  has,  for  many  years,  settled  upon 


EXPOSITION  OF  IDEAS  287 

the  third  method.  With  all  its  admitted  limitations  it  seems  to  be 
the  best  for  an  office  which  is  expected  to  find  out  information  on  a 
great  variety  of  subjects  in  a  limited  time,  and  with  the  least  amount 
of  effort. 

Data  tor  Reference 

Some  description  of  its  practical  workings  may  be  of  interest: 
All  the  technical  papers  of  the  office  pass  on  to  the  desk  of  the 
head  of  the  office  and  are  at  least  looked  over  (not  read)  by  him. 
Articles  important  to  his  particular  specialty  are  checked  with 
pencil,  and  articles  of  especial  interest  are  looked  over  with  care 
and  double  checked.  Once  in  a  long  while  data  important  enough 
to  go  to  the  data  file  are  noted.  This  is  either  especially  abstracted 
by  the  stenographer,  or,  if  a  diagram  or  cost  data,  perhaps  traced 
in  the  drafting  room,  all  on  transparent  paper  for  copying  purposes. 
Special  data  of  this  kind,  on  83^2  X  ii-in.  sheets,  are  filed  in  the 
office  data  file  (a  separate  but  common  standard  correspondence 
file).  From  the  data  file  loose-leaf  working  note-books  are  made 
up  from  blueprints  for  office  or  travel  purposes.  They  are  altered, 
refilled,  amended  and  sorted  back  from  time  to  time  as  needed  to 
keep  them  of  usable  volume  and  usefully  up-do-date. 

The  technical  journals,  with  checked  articles,  go  to  the  office 
clerk  or  the  stenographer  at  odd  hours,  or  the  librarian  if  one  can 
be  afforded,  and  the  useful  articles  are  removed  by  tearing  them 
out  with  a  ruler.  They  are  folded,  usually  once,  to  standard  size, 
with  one  edge  lap  left  for  binding,  and  are  then  filed  in  a  subject 
index  file,  like  current  correspondence.  The  Dewey  Decimal  sys- 
tem, especially  arranged  for  the  office,  is  used,  but  only  as  a  general 
subject  plan.  When  the  file  is  full,  portions  of  its  contents,  es- 
pecially that  which  is  most  useful,  are  simply  bound  in  plain  paste- 
board covers  and  placed  in  the  library  shelves,  with  titles.  Such  a 
book  (or  many  books)  would  contain  all  the  recent  articles  thought 
to  be  of  special  value  on  a  given  single  subject.  The  remaining 
portions  of  the  technical  paper  are  thrown  away,  but  in  a  large 
office,  warranting  the  expense,  duplicate  bound  copies  can  be  kept 
as  well,  with  the  general  published  index  as  their  key. 

Objections  and  'Advantages 

The  objections  to  this  system  are  as  follows: 

First,  it  is  too  expensive  for  any  but  the  most  important  offices 


288    COMPOSITION  OF  TECHNICAL  PAPERS 

doing  specialized  work.  Second,  data  accumulate  almost  too  fast 
unless  rigidly  kept  down  to  a  minimum.  Third,  it  requires  some 
personal  attention  of  the  head  of  the  ofl5ce,  a  competent  assistant, 
or  the  employment  of  a  regular  librarian. 

The  advantages  are : 

First,  it  compels  the  ofl&ce  head  to  know  all  the  time  what  is 
being  published  in  current  engineering  literature,  if  only  by  in- 
spection. Second,  it  removes  all  intervening  indexes  between  the 
searcher  and  the  final  repository  in  bound  volume.  Third,  it  keeps 
one's  library  usefully  up-to-date  on  all  lines  in  which  one  should  be 
especially  interested.  Fourth,  it  is  economical  of  final  shelf  room 
and  cost. 

Obviously,  one  should  not  start  so  elaborate  a  system  as  this 
unless  he  is  fairly  sure  of  the  special  line  of  engineering  to  which 
his  life  will  be  devoted.  Otherwise,  waste  effort  and  discourage- 
ment will  be  certain.  It  is  not  to  be  recommended  to  the  young 
man,  but  only  to  the  mature  man  of  early  middle  life  when  his  work 
clearly  indicates  the  necessity  for  it.  It  is,  however,  the  prime 
requisite  of  the  engineering  specialist.  To  him  some  such  a  system 
is  invaluable.  Not  a  few  consulting  engineers  use  this  standardized 
system  interchangeably,  particularly  the  data  file,  thereby  greatly 
increasing  its  usefulness  to  one  another  as  a  joint  effort. 

We  come  finally  to  the  mature  and  experienced  engineer  of  ad- 
vancing years.  How  can  he  make  engineering  and  technical 
literature  of  use?  It  is  safe  to  say  that  when  an  engineer  has  much 
passed  fifty  or  sixty  years  of  age  and  has  led  an  active  life,  his 
need  for  engineering  literature  lessens.  Out  of  the  mass  of  detail 
which  seemed  to  him  so  overwhelming  and  endless  in  his  youth 
and  early  manhood,  fundamental  principles  emerge  like  peaks  out 
of  the  clouds,  and  upon  these  as  foundation  all  detail  classifies  itself 
simply  and  naturally,  and  therefore,  he  feels  less  need  for  accumu- 
lated data  or  particular  description.  Probably  no  one  enjoys  en- 
gineering reading  as  does  the  mature  engineer,  for  he  can  read 
between  the  lines  and  find  much  to  instruct  as  well  as  interest,  and 
yet  while  he  is  probably  the  most  interested  and  intelligent  reader  of 
engineering  literature  that  the  journals  have,  his  ambition  as  a 
collector  is  gone  and  filing  systems  no  longer  appeal  to  him. 

If  his  acquaintance  is  wide,  he  reads  with  interest  the  accomplish- 
ments of  his  friends,  and  the  addresses  of  society  presidents  and 
articles  on  the  ethics  of  the  profession.     Of  failures  he  is  the  keen 


EXPOSITION  OF  IDEAS  289 

student.  The  personal  column  appeals  to  him,  and  if  he  is  of  right- 
mindedness  he  is  conscious  of  more  pleasure  than  formerly  in  the 
accomplishments  of  those  who  have  succeeded  and  succeeded  well 
in  dire  and  burdensome  responsibility.  More  often  than  the  young 
man  he  will  turn  back  for  his  satisfaction  to  papers  that  served  him 
well  in  times  past,  and  perhaps  smile  at  the  lack  of  improvement 
that  later  attempts  to  deal  with  their  subject  often  show. 

Technical  papers,  along  with  the  technical  societies  and  their 
proceedings,  form  the  repository  of  the  professions;  they  are  the 
interchange  of  experience,  the  common  store  upon  which  we  all 
draw.  Without  them  we  would  be  strangely  helpless.  We  are 
indebted  to  every  one  more  or  less  who  records  his  experience  for 
the  common  use,  and  that  debt  we  should  endeavor  to  helpfully 
repay  in  kind,  but  wisely,  concisely  and  thoughtfully. 

Reading  Technical  Journals^ 

In  the  qualifying  tests  of  marksmanship  which  are  now  a  regular 
part  of  our  army  routine,  it  is  always  instructive  to  stand  behind  a 
pair  of  men  on  the  firing  line  at  a  rifle  range  and  watch  the  effect 
of  their  shots.  Rifles,  ammunition,  targets  and  range  are  the  same 
for  both,  yet  one  will  score  an  unbroken  string  of  bull's-eyes  and 
*'four's"  while  the  other  will  turn  in  a  card  of  "three's,"  "two's" 
and  "misses."  The  first  man  knows  how  to  use  his  weapon;  the 
second,  with  the  same  weapon,  gets  poor  results. 

These  two  soldiers  are  typical  of  two  classes  of  readers  of  the 
technical  journal.  To  each  class  the  publisher  sends  the  same  sort 
of  munitions  in  printed  form  each  week.  One  will  take  this  mate- 
rial and  with  it  score  effectively  in  his  own  work,  while  the  other 
receives,  comparatively,  little  benefit.  In  this  issue  John  W.  Alvord 
gives  an  instructive  lesson  in  the  use  of  the  technical  periodical. 
His  paper  was  read  last  week  before  the  Federation  of  Trade  Press 
Associations  in  Chicago  and  is  reprinted  on  page  375.  He  analyzes 
the  cases  of  the  young  engineer,  the  mature  reader,  who  "has  no 
time  to  read,"  and  the  veteran  with  years  of  experience  behind  him. 
For  each  the  modern  technical  journal  has  something  to  offer,  if 
the  reader  will  only  take  the  trouble  to  learn  how  to  find  it.     Mr. 

1  Editorial  comment  on  Mr.  Alvord's  paper  reprinted  from  the  Engineering 
Record  for  October  3,  19 14,  by  permission  of  the  publishers. 


290    COMPOSITION  OF  TECHNICAL  PAPERS 

Alvord's  paper  is  replete  with  helpful  hints  on  what  to  read,  what  not 
to  read  and  how  to  preserve  engineering  data  for  future  reference. 
The  editor  of  to-day,  in  contrast  with  his  predecessor  of  a  decade 
ago,  faces  each  morning  an  imposing  mound  of  manuscript — far 
in  excess  of  the  space  available  for  contributions — and  from  this  he 
selects  his  articles.  The  field  of  civil  engineering  is  so  broad  that  a 
wide  range  of  subjects  must  be  covered  by  the  paper  which  con- 
scientiously serves  all  its  readers.  Manifestly  every  story  will 
not  interest  every  subscriber.  In  these  days  of  specialization, 
therefore,  the  reader  must  learn  to  estimate  the  value  of  each 
article  from  the  standpoint  of  his  own  needs  and  concentrate  upon 
those  which  apply  to  his  particular  work.  Technical  journalism 
has  by  no  means  reached  a  stage  which  might  be  called  perfection. 
Even  an  editor  will  admit  this  frankly,  but  the  technical  paper  has 
established  for  itself  a  place  in  engineering  progress  and  with  the 
cooperation  of  its  readers  an  even  larger  field  of  usefulness  lies 
before  it. 


The  Method  of  Scientific  Investigation^ 
Thomas  Henry  Huxley 

[No  apology  need  be  made  for  again  reprinting  this 
much  used  lecture  by  Huxley.  Huxley's  mastery  of  ex- 
position consists  largely  in  his  ability  to  adopt  the  point 
of  view  of  his  audience.  The  elements  of  good  exposition 
to  be  noted  here  are:  (i)  his  clear  inductive  explanation  of 
abstract  terms,  (2)  his  wealth  of  simple  illustration,  (3) 
his  clean-cut  division  of  material,  and  (4)  his  easy  style, 
characterized  by  playfulness  of  manner,  sympathy  with 
his  audience,  and  avoidance  of  technical  or  otherwise 
difficult  words.] 

The  method  of  scientific  investigation  is  nothing  but  the  expres- 
sion of  the  necessary  mode  of  working  of  the  human  mind.  It  is 
simply  the  mode  at  which  all  phenomena  are  reasoned  about, 

1  The  first  part  of  the  third  lecture  of  a  series  of  Six  Lectures  to  Workingmen 
on  the  Phenomena  of  Organic  Nature,  1863. 


EXPOSITION  OF  IDEAS  291 

rendered  precise  and  exact.  There  is  no  more  difference,  but  there 
is  just  the  same  kind  of  difference,  between  the  mental  operations  of 
a  man  of  science  and  those  of  an  ordinary  person,  as  there  is  between 
the  operations  and  methods  of  a  baker  or  of  a  butcher  weighing  out 
his  goods  in  common  scales,  and  the  operations  of  a  chemist  in 
performing  a  difficult  and  complex  analysis  by  means  of  his  balance 
and  finely-graduated  weights.  It  is  not  that  the  action  of  the 
scales  in  the  one  case,  and  the  balance  in  the  other,  differ  in  the 
principles  of  their  construction  or  manner  of  working;  but  the  beam 
of  one  is  set  on  an  infinitely  finer  axis  than  the  other,  and  of  course 
turns  by  the  addition  of  a  much  smaller  weight. 

You  will  understand  this  better,  perhaps,  if  I  give  you  some 
familiar  example.  You  have  all  heard  it  repeated,  I  dare  say,  that 
men  of  science  work  by  means  of  Induction  and  Deduction,  and 
that  by  the  help  of  these  operations,  they,  in  a  sort  of  sense,  wring 
from  Nature  certain  other  things,  which  are  called  Natural  Laws, 
and  Causes,  and  that  out  of  these,  by  some  cunning  skill  of  their 
own,  they  build  up  Hypotheses  and  Theories.  And  it  is  imagined 
by  many,  that  the  operations  of  the  common  mind  can  be  by  no 
means  compared  with  these  processes,  and  that  they  have  to  be 
acquired  by  a  sort  of  special  apprenticeship  to  the  craft.  To  hear 
all  these  large  words,  you  would  think  that  the  mind  of  a  man  of 
science  must  be  constituted  differently  from  that  of  his  fellow- men; 
but  if  you  will  not  be  frightened  by  terms,  you  will  discover  that 
you  are  quite  wrong,  and  that  all  these  terrible  apparatus  are  being 
used  by  yourselves  every  day  and  every  hour  of  your  lives. 

There  is  a  well-known  incident  in  one  of  Moliere's  plays,  where 
the  author  makes  the  hero  express  unbounded  delight  on  being 
told  that  he  had  been  talking  prose  during  the  whole  of  his  life. 
In  the  same  way,  I  trust,  that  you  will  take  comfort,  and  be  de- 
lighted with  yourselves,  on  the  discovery  that  you  have  been  acting 
on  the  principles  of  inductive  and  deductive  philosophy  during  the 
same  period.  Probably  there  is  not  one  here  who  has  not  in  the 
course  of  the  day  had  occasion  to  set  in  motion  a  complex  train  of 
reasoning,  of  the  very  same  kind,  though  differing  of  course  in 
degree,  as  that  which  a  scientific  man  goes  through  in  tracing  the 
causes  of  natural  phenomena. 

A  very  trivial  circumstance  will  serve  to  exemplify  this.  Suppose 
you  go  into  a  fruiterer's  shop,  wanting  an  apple, — you  take  up  one, 
and,  on  biting  it,  you  find  it  is  sour;  you  look  at  it,  and  see  that  it  is 


292    COMPOSITION  OF  TECHNICAL  PAPERS 

hard  and  green.  You  take  up  another  one,  and  that  too  is  hard, 
green,  and  sour.  The  shopman  offers  you  a  third;  but,  before  biting 
it,  you  examine  it,  and  find  that  it  is  hard  and  green,  and  you 
immediately  say  that  you  will  not  have  it,  as  it  must  be  sour,  like 
those  that  you  have  already  tried. 

Nothing  can  be  more  simple  than  that,  you  think;  but  if  you  will 
take  the  trouble  to  analyze  and  trace  out  into  its  logical  elements 
what  has  been  done  by  the  mind,  you  will  be  greatly  surprised.  In 
the  first  place,  you  have  performed  the  operation  of  Induction. 
You  found  that,  in  two  experiences,  hardness  and  greenness  in 
apples  went  together  with-sourness.  It  was  so  in  the  first  case, 
and  it  was  confirmed  by  the  second.  True,  it  is  a  very  small  basis, 
but  still  it  is  enough  to  make  an  induction  from;  you  generalize 
the  facts,  and  you  expect  to  find  sourness  in  apples  where  you  get 
hardness  and  greenness.  You  found  upon  that  a  general  law,  that 
all  hard  and  green  apples  are  sour;  and  that,  so  far  as  it  goes,  is  a 
perfect  induction.  Well,  having  got  your  natural  law  in  this  way, 
when  you  are  offered  another  apple  which  you  find  is  hard  and 
green,  you  say,  "All  hard  and  green  apples  are  sour;  this  apple  is 
hard  and  green,  therefore  this  apple  is  sour."  That  train  of  reason- 
ing is  what  logicians  call  a  syllogism,  and  has  all  its  various  parts 
and  terms, — its  major  premiss,  its  minor  premiss,  and  its  conclu- 
sion. And,  by  the  help  of  further  reasoning,  which,  if  drawn  out, 
would  have  to  be  exhibited  in  two  or  three  other  syllogisms,  you 
arrive  at  your  final  determination,  "I  will  not  have  that  apple." 
So  that,  you  see,  you  have,  in  the  first  place,  established  a  law  by 
Induction,  and  upon  that  you  have  founded  a  Deduction,  and 
reasoned  out  the  special  conclusion  of  the  particular  case.  Well 
now,  suppose,  having  got  your  law,  that  at  some  time  afterwards, 
you  are  discussing  the  qualities  of  apples  with  a  friend:  you  will 
say  to  him,  "It  is  a  very  curious  thing, — but  I  find  that  all  hard 
and  green  apples  are  sour!"  Your  friend  says  to  you,  "But  how 
do  you  know  that?"  You  at  once  reply,  "Oh,  because  I  have  tried 
them  over  and  over  again,  and  have  always  found  them  to  be  so." 
Well,  if  we  were  talking  science  instead  of  common  sense,  we  should 
call  that  an  Experimental  Verification.  And,  if  still  opposed,  you 
go  further,  and  say,  "I  have  heard  from  the  people  in  Somersetshire 
and  Devonshire,  where  a  large  number  of  apples  are  grown,  that 
they  have  observed  the  same  thing.  It  is  also  found  to  be  the  case 
in  Normandy,  and  in  North  America.    In  short,  I  find  it  to  be  the 


EXPOSITION  OF  IDEAS  293 

universal  experience  of  mankind  wherever  attention  has  been 
directed  to  the  subject."  Whereupon,  your  friend,  unless  he  is  a 
very  unreasonable  man,  agrees  with  you,  and  is  convinced  that  you 
are  quite  right  in  the  conclusion  you  have  drawn.  He  believes, 
although  perhaps  he  does  not  know  he  believes  it,  that  the  more 
extensive  Verifications  are, — that  the  more  frequently  experiments 
have  been  made,  and  results  of  the  same  kind  arrived  at,  —that  the 
more  varied  the  conditions  under  which  the  same  results  are  at- 
tained, the  more  certain  is  the  ultimate  conclusion,  and  he  dis- 
putes the  question  no  further.  He  sees  that  the  experiment  h^s 
been  tried  under  all  sorts  of  conditions,  as  to  time,  place,  and 
people,  with  the  same  result;  and  he  says  with  you,  therefore, 
that  the  law  you  have  laid  down  must  be  a  good  one,  and  he  must 
believe  it. 

In  science  we  do  the  same  thing; — the  philosopher  exercises  pre- 
cisely the  same  faculties,  though  in  a  much  more  delicate  manner. 
In  scientific  inquiry  it  becomes  a  matter  of  duty  to  expose  a  sup- 
posed law  to  every  possible  kind  of  verification,  and  to  take  care, 
moreover,  that  this  is  done  intentionally,  and  not  left  to  a  mere 
accident,  as  in  the  case  of  the  apples.  And  in  science,  as  in  common 
life,  our  confidence  in  a  law  is  in  exact  proportion  to  the  absence  of 
variation  in  the  result  of  oar  experimental  verifications.  For 
instance,  if  you  let  go  your  grasp  of  an  article  you  may  have  in  your 
hand,  it  will  immediately  fall  to  the  ground.  That  is  a  very  com- 
mon verification  of  one  of  the  best  established  laws  of  nature — that 
of  gravitation.  The  method  by  which  men  of  science  establish  the 
existence  of  that  law  is  exactly  the  same  as  that  by  which  we  have 
established  the  trivial  proposition  about  the  sourness  of  hard  and 
green  apples.  But  we  believe  it  in  such  an  extensive,  thorough,  and 
unhesitating  manner  because  the  universal  experience  of  mankind 
verifies  it,  and  we  can  verify  it  ourselves  at  any  time;. and  that  is  the 
strongest  possible  foundation  on  which  any  natural  law  can  rest. 

So  much,  then,  by  way  of  proof  that  the  method  of  establishing 
laws  in  science  is  exactly  the  same  as  that  pursued  in  common  life. 
Let  us  now  turn  to  another  matter  (though  really  it  is  but  another 
phase  of  the  same  question),  and  that  is,  the  method  by  which, 
from  the  relations  of  certain  phenomena,  we  prove  that  some  stand 
in  the  position  of  causes  towards  the  others. 

I  want  to  put  the  case  clearly  before  you,  and  I  will  therefore 
show  you  what  I  mean  by  another  familiar  example.  I  will  sup- 
19 


294  'COMPOSITION  OF  TECHNICAL  PAPERS 

pose  that  one  of  you,  on  coming  down  in  the  morning  to  the  parlour 
of  your  house,  finds  that  a  tea-pot  and  some  spoons  which  had  been 
left  in  the  room  on  the  previous  evening  are  gone, — the  window  is 
open,  and  you  observe  the  mark  of  a  dirty  hand  on  the  window- 
frame,  and  perhaps,  in  addition  to  that,  you  notice  the  impress  of  a 
hob-nailed  shoe  on  the  gravel  outside.  All  these  phenomena  have 
struck  your  attention  instantly,  and  before  two  seconds  have  passed 
you  say,  "Oh,  somebody  has  broken  open  the  window,  entered  the 
room,  and  run  off  with  the  spoons  and  the  tea-pot!"  That  speech 
is  out  of  your  mouth  in  a  moment.  And  you  will  probably  add, 
"I  know  there  has;  I  am  quite  sure  of  it!"  You  mean  to  say  exactly 
what  you  know;  but  in  reality  you  are  giving  expression  to  what  is, 
in  all  essential  particulars,  an  Hypothesis.  You  do  not  know  it  at 
all;  it  is  nothing  but  an  hypothesis  rapidly  framed  in  your  own  mind! 
And,  it  is  an  hypothesis  founded  on  a  long  train  of  inductions  and 
deductions. 

What  are  those  inductions  and  deductions,  and  how  have  you 
got  at  this  hypothesis?  You  have  observed,  in  the  first  place,  that 
the  window  is  open;  but  by  a  train  of  reasoning  involving  many 
Inductions  and  Deductions,  you  have  probably  arrived  long  before 
at  the  General  Law^ — and  a  very  good  one  it  is — that  windows  do 
not  open  of  themselves;  and  you  therefore  conclude  that  something 
has  opened  the  window.  A  second  general  law  that  you  have 
arrived  at  in  the  same  way  is,  that  tea-pots  and  spoons  do  not  go  out 
of  a  window  spontaneously,  and  you  are  satisfied  that,  as  they  are 
not  now  where  you  left  them,  they  have  been  removed.  In  the 
third  place,  you  look  at  the  marks  on  the  window-sill,  and  the  shoe- 
marks  outside,  and  you  say  that  in  all  previous  experience  the 
former  kind  of  mark  has  never  been  produced  by  anything  else 
but  the  hand  of  a  human  being;  and  the  same  experience  shows  that 
no  other  animal  but  man  at  present  wears  shoes  with  hob-nails  in 
them  such  as  would  produce  the  marks  in  the  gravel.  I  do  not 
know,  even  if  we  could  discover  any  of  those  "missing  links"  that 
are  talked  about,  that  they  would  help  us  to  any  other  conclusion ! 
At  any  rate  the  law  which  states  our  present  experience  is  strong 
enough  for  my  present  purpose.  You  next  reach  the  conclusion, 
that  as  these  kinds  of  marks  have  not  been  left  by  any  other  ani- 
mals than  men,  or  are  liable  to  be  formed  in  any  other  way  than 
by  a  man's  hand  and  shoe,  the  marks  in  question  have  been  formed 
by  a  man  in  that  way.     You  have,  further,  a  general  law,  founded 


EXPOSITION  OF  IDEAS  295 

on  observation  and  experience,  and  that,  too,  is,  I  am  sorry  to  say, 
a  very  universal  and  unimpeachable  one, — that  some  men  are 
thieves;  and  you  assume  at  once  from  all  these  premisses — and 
that  is  what  constitutes  your  hypothesis — that  the  man  who  made 
the  marks  outside  and  on  the  window-sill,  opened  the  window,  got 
into  the  room,  and  stole  your  tea-pot  and  spoons.  You  have  now 
arrived  at  a  Vera  Causa; — you  have  assumed  a  Cause  which  it  is 
plain  is  competent  to  produce  all  the  phenomena  you  have  observed. 
You  can  explain  all  these  phenomena  only  by  the  hypothesis  of  a 
thief.  But  that  is  a  hypothetical  conclusion,  of  the  justice  of  which 
you  have  no  absolute  proof  at  all;  it  is  only  rendered  highly  probable 
by  a  series  of  inductive  and  deductive  reasonings. 

I  suppose  your  first  action,  assuming  that  you  are  a  man  of 
ordinary  common  sense,  and  that  you  have  established  this  hy- 
pothesis to  your  own  satisfaction,  will  very  likely  be  to  go  ofif  for  the 
police,  and  set  them  on  the  track  of  the  burglar,  with  the  view  to  the 
recovery  of  your  property.  But  just  as  you  are  starting  with  this 
object,  some  person  comes  in,  and  on  learning  what  you  are  about, 
says,  "My  good  friend,  you  are  going  on  a  great  deal  too  fast. 
How  do  you  know  that  the  man  who  really  made  the  marks  took  the 
spoons?  It  might  have  been  a  monkey  that  took  them,  and 
the  man  may  have  merely  looked  in  afterwards."  You  would 
probably  reply,  "Well,  that  is  all  very  well,  but  you  see  it  is  con- 
trary to  all  experience  of  the  way  tea-pots  and  spoons  are  ab- 
stracted; so  that,  at  any  rate,  your  hypothesis  is  less  probable  than 
mine."  While  you  are  talking  the  thing  over  in  this  way,  another 
friend  arrives,  one  of  that  good  kind  of  people  that  I  was  talking  of 
a  little  while  ago.  And  he  might  say,  "Oh,  my  dear  sir,  you  are 
certainly  going  on  a  great  deal  too  fast.  You  are  most  presumptu- 
ous. You  admit  that  all  these  occurrences  took  place  when  you 
were  fast  asleep,  at  a  time  when  you  could  not  possibly  have  known 
anything  about  what  was  taking  place.  How  do  you  know  that 
the  laws  of  Nature  are  nof  suspended  during  the  night?  It  may  be 
that  there  has  been  some  kind  of  supernatural  interference  in  this 
case."  In  point  of  fact,  he  declares  that  your  hypothesis  is  one  of 
which  you  can  not  at  all  demonstrate  the  truth,  and  that  you  are 
by  no  means  sure  that  the  laws  of  Nature  are  the  same  when  you  are 
asleep  as  when  you  are  awake. 

Well,  now,  you  can  not  at  the  moment  answer  that  kind  of  reason- 
ing.    You  feel  that  your  worthy  friend  has  you  somewhat  at  a 


296    COMPOSITION  OF  TECHNICAL  PAPERS 

disadvantage.  You  will  feel  perfectly  convinced  in  your  own  mind, 
however,  that  you  are  quite  right,  and  you  say  to  him,  "My  good 
friend,  I  can  only  be  guided  by  the  natural  probabilities  of  the  case, 
and  if  you  will  be  kind  enough  to  stand  aside  and  permit  me  to  pass, 
I  will  go  and  fetch  the  police."  Well,  we  will  suppose  that  your 
journey  is  successful,  and  that  by  good  luck  you  meet  with  a  police- 
man; that  eventually  the  burglar  is  found  with  your  property  on 
his  person,  and  the  marks  correspond  to  his  hand  and  to  his  boots. 
Probably  any  jury  would  consider  those  facts  a  very  good  experi- 
mental verification  of  your  hypothesis,  touching  the  cause  of  the 
abnormal  phenomena  observed  in  your  parlour,  and  would  act 
accordingly. 

Now,  in  this  supposititious  case,  I  have  taken  phenomena  of  a 
very  common  kind,  in  order  that  you  might  see  what  are  the  different 
steps  in  an  ordinary  process  of  reasoning,  if  you  will  only  take  the 
trouble  to  analyze  it  carefully.  All  the  operations  I  have  described, 
you  will  see,  are  involved  in  the  mind  of  any  man  of  sense  in  lead- 
ing him  to  a  conclusion  as  to  the  course  he  should  take  in  order  to 
make  good  a  robbery  and  punish  the  offender.  I  say  that  you  are 
led,  in  that  case,  to  your  conclusion  by  exactly  the  same  train  of 
reasoning  as  that  which  a  man  of  science  pursues  when  he  is  en- 
deavouring to  discover  the  origin  and  laws  of  the  most  occult  phe- 
nomena. The  process  is,  and  always  must  be,  the  same;  and  pre- 
cisely the  same  mode  of  reasoning  was  employed  by  Newton  and 
Laplace  in  their  endeavours  to  discover  and  define  the  causes  of 
the  movements  of  the  heavenly  bodies,  as  you,  with  your  own 
common  sense,  would  employ  to  detect  a  burglar.  The  only  differ- 
ence is,  that  the  nature  of  the  inquiry  being  more  abstruse,  every 
step  has  to  be  most  carefully  watched,  so  that  there  may  not  be  a 
single  crack  or  flaw  in  your  hypothesis.  A  flaw  or  crack  in  many 
of  the  hypotheses  of  daily  life  may  be  of  little  or  no  moment  as 
affecting  the  general  correctness  of  the  conclusions  at  which  we  may 
arrive;  but  in  a  scientific  inquiry  a  felfefj,  great  or  small,  is  always 
of  importance,  and  is  sure  to  be  in  the  long  run  constantly  produc- 
tive of  mischievous,  if  not  fatal  results. 

Do  not  allow  yourselves  to  be  misled  by  the  common  notion  that 
an  hypothesis  is  untrustworthy  simply  because  it  is  an  hypoth- 
esis. It  is  often  urged,  in  respect  to  some  scientific  conclusion, 
that,  after  all,  it  is  only  an  hypothesis.  But  what  more  have  we  to 
guide  us  in  nine-tenths  of  the  most  important  affairs  of  daily  life 


EXPOSITION  OF  IDEAS  297 

than  hypotheses,  and  often  very  ill-based  ones?  So  that  in  science, 
where  the  evidence  of  an  hypothesis  is  subjected  to  the  most 
rigid  examination,  we  may  rightly  pursue  the  same  course.  You 
may  have  hypotheses  and  hypotheses.  A  man  may  say,  if  he  likes, 
that  the  moon  is  made  of  green  cheese:  that  is  an  hypothesis.  But 
another  man,  who  has  devoted  a  great  deal  of  time  and  attention 
to  the  subject,  and  availed  himself  of  the  most  powerful  telescopes 
and  the  results  of  the  observations  of  others,  declares  that  in 
his  opinion  it  is  probably  composed  of  materials  very  similar  to 
those  of  which  our  own  earth  is  made  up:  and  that  is  also  only  an 
hypothesis.  But  I  need  not  tell  you  that  there  is  an  enormous 
difference  in  the  value  of  the  two  hypotheses.  That  one  which  is 
based  on  sound  scientific  knowledge  is  sure  to  have  a  corresponding 
value;  and  that  which  is  a  mere  hasty  random  guess  is  likely  to 
have  but  little  value.  Every  great  step  in  our  progress  in  discover- 
ing causes  has  been  made  in  exactly  the  same  way  as  that  which  I 
have  detailed  to  you.  A  person  observing  the  occurrence  of  certain 
facts  and  phenomena  asks,  naturally  enough,  what  process,  what 
kind  of  operation  known  to  occur  in  nature  applied  to  the  particular 
case,  will  unravel  and  explain  the  mystery?  Hence  you  have  the 
scientific  hypothesis;  and  its  value  will  be  proportionate  to  the  care 
and  completeness  with  which  its  basis  had  been  tested  and  verified. 
It  is  in  these  matters  as  in  the  commonest  affairs  of  practical  life: 
the  guess  of  the  fool  will  be  folly,  while  the  guess  of  the  wise 
man  will  contain  wisdom.  In  all  cases,  you  see  that  the  value 
of  the  result  depends  on  the  patience  and  faithfulriess  with  which 
the  investigator  applies  to  his  hypothesis  every  possible  kind  of 
verification. 

The  Web-foot  Engineer^ 
Benjamin  Brooks 

[The  following  is  a  "popular  science"  exposition,  an 
explanation  of  the  work  of  the  "web-foot"  engineer 
stripped  of  its  technicalities  and  otherwise  adapted  to 
the  understanding  of  the  general  reader.  Among  the 
compositional  elements  which  should  be  noted  here  are: 

1  Reprinted  by  permission  of  the  publishers  from  McClure's  Magazine, 
Vol.  XXXIII.  p.  73. 


2  98    COMPOSITION  OF  TECHNICAL  PAPERS 

(i)  The  clear  arrangement  and  careful  indication  of  divi- 
sions; (2)  the  adaptation  to  the  reader,  involving  an  ex- 
pository plan  by  which  the  simple  outlines  of  the  engi- 
neering processes  explained  are  given  first  and  the  more 
complicated  details  later,  an  avoidance  of  technical  terms, 
and  frequent  striking  analogies  which  the  general  reader 
can  readily  understand;  and  (3)  the  color  and  individu- 
ality of  the  style,  which  is  characterized  by  concreteness 
and  novelty  of  expression,  easy  humor,  and  pleasing 
suggestion  of  big  men  dauntlessly  solving  big  problems.] 

While  the  "tallest  building  in  the  world" — which  is  always 
being  built  somewhere  in  New  York — continues  to  absorb  popular 
wonder  and  attention,  and  the  great  cantilevers  and  suspension- 
bridges  continue  to  bear  up  under  their  weight  of  criticism  without 
visible  means  of  support,  the  most  important  but  least  spectacular 
individual  concerned  in  their  existence  continues  his  unobtrusive 
subterranean  operations  almost  unknown,  except  as  he  may 
from  time  to  time  annoy  us  with  the  blocking  of  a  thoroughfare  or 
the  creation  of  a  local  earthquake.  Thus  the  term  "skyscraper" 
is  an  old  one,  while  the  term  "earthscraper"  was  invented  but 
yesterday.  I  have  spoken  of  this  retiring  person  as  web-footed 
because,  as  with  ducks  and  cranes  and  other  animals  thus  endowed 
by  nature,  the  business  of  his  life  is  in  the  mud,  the  shifty  quick- 
sand, and  under  water;  and  whatever  he  may  lack  in  the  spectacular 
or  picturesque,  he  is  nevertheless  most  worthy  of  notice  for  his 
unequalled  ingenuity. 

The  web-foot  engineer  has  three  main  problems  to  deal  with: 
to  support  a  tremendous  weight  over  soft  mud  or  quicksand;  to 
open  and  maintain  a  clear  passage  through  it;  to  drain  it  oflf  and 
eliminate  it  altogether.  Out  of  these  three  main  problems  grow 
an  endless  combination  of  difficulties  that  he  must  devise  means 
of  overcoming;  but  in  all  of  them  enters  his  arch-enemy,  water 
— water,  the  basis  of  all  big  engineering,  locater  of  railways  and 
thoroughfares,  distributor  of  population,  maker  of  treaties, 
destroyer  of  man's  half-baked,  faint-hearted  attempts,  but  con- 
server  of  his  truly  great  works. 

There  is  an  old,  shop- worn  fallacy  that  the  great  man  is  always 


EXPOSITION  OF  IDEAS  299 

at  hand  awaiting  the  occasion  that  will  bring  him  out  of  oblivion 
and  put  him  on  his  mettle;  but  the  two  greatest  cities  in  the  world 
both  waited  years  in  an  overcrowded,  river-girt  condition,  loudly 
proclaiming  the  occasion  for  a  great  man;  yet  it  was  a  long  time 
before  he  came  to  liberate  them.  He  appeared  only  in  the  last 
century  to  the  city  of  London  after  that  town  had  overflowed  its 
bridges  for  generations,  and  he  presented  a  scheme  for  driving  a 
tunnel  under  the  Thames  through  the  comparatively  soft  clay. 
Everybody  knew  that  so  large  a  hole  as  a  tunnel  could  not  be  dug 
and  kept  open  under  the  Thames;  but  if  a  short,  portable  piece  of 
completed  tunnel  could  be  continuously  pushed  ahead  and  added 
to  from  behind,  what  then?  He  conceived  a  steel  contrivance  just 
a  trifle  bigger  around  than  the  tunnel  was  to  be,  shaped  in  about  the 
proportions  of  a  baking-powder  can,  with  no  bottom  and  no  top, 
but  having  a  diaphragm  or  partition  across  the  middle  of  it. 
When  this  had  been  sunk  down  and  started  on  the  line  of  the  tunnel, 
the  forward  part  of  the  shell  would  hold  up  the  overhanging 
mud  sufficiently  so  that  men  could  work  through  little  doorways  in 
the  partition,  digging  the  earth  from  in  front  and  loading  it  into 
cars  to  be  carried  out  behind;  and  at  the  same  time,  on  the  interior 
of  the  after  portion,  other  men  could  bolt  together  the  steel  or  iron 
sections  of  the  tunnel  lining. 

A  short  section  having  been  completed  in  this  manner,  the  whole 
machine  could  push  itself  ahead  with  a  kick — that  is,  with  powerful 
hydraulic  jacks  pressing  against  the  completed  part  of  the  tunriel. 
Imagine  having  forced  a  large,  empty  sugar  barrel  horizontally  into 
a  bank  of  earth,  first  having  knocked  out  both  heads.  By  crawling 
into  the  barrel  a  man  could,  with  considerable  discomfort  and  per- 
spiration, dig  away  the  earth  some  little  distance  in  advance  of  the 
barrel,  and,  given  something  to  kick  against,  he  could  push  himself 
and  his  barrel  farther  into  the  cavity  he  had  dug.  Now,  if  another 
man  were  to  hand  him  the  necessary  staves  and  internal  hoops,  he 
could  build  a  second  and  slightly  smaller  barrel  partly  inside  of 
the  first  one.  He  might  then  do  more  digging  and  more  pushing 
ahead,  until  he  had  proceeded  far  enough  to  build  a  second  small 
barrel  and  fit  it  tightly  to  the  end  of  the  first  small  barrel.  In 
this  way,  since  a  small  barrel  always  lapped  partly  inside  of  the 
big  one  in  which  he  worked,  the  earth  could  never  cave  in  and  cut 
him  off  from  daylight;  and  so  long  as  he  was  provided  with  staves, 
hoops,  food,  water,  and  air,  he  could  burrow  on  indefinitely. 


300    COMPOSITION  OF  TECHNICAL  PAPERS 

Such,  in  a  nutshell,  was  the  idea  of  a  certain  web-foot  engineer, 
Sir  Marc  Brunei,  in  1824 — the  simplest,  best,  most  ingenious  idea 
that  has  occurred  to  engineers  in  many  years.  The  great  cities 
had  waited  for  it  so  long  that  they  accepted  it  ravenously.  Tunnels 
burrowed  under  the  Thames,  the  Seine,  the  Hudson.  Poor  old 
tunnels  that  had  set  out  without  it  and  gone  bankrupt  at  the  dis- 
couraging rate  of  a  few  inches  a  week,  took  on  a  new  lease  of  life 
and  set  out  again  at  many  feet  a  day;  and  they  are  going  yet — all 
day  and  all  night,  steadily,  blindly,  but  surely,  on  under  the  rivers 
to  set  the  cities  free. 

Of  course  the  original  idea  has  to  be  modified  somewhat  for 
every  particular  tunnel  and  for  each  variety  of  mud.  If  the  mud 
is  full  of  gravel  and  boulders,  the  forward  half  of  the  machine  has  to 
be  worked  under  compressed  air  to  balance  the  pressure  of  earth 
and  water;  and  the  workers  have  to  be  provided  with  safety  locks 
in  case  of  a  sudden  inrush  of  water.  If  you  invert  a  glass  in  a  bowl 
of  water  and  press  it  down,  the  water  will  not  rise  to  any  extent 
in  the  glass.  On  this  principle,  little  inverted  steel  pockets  are 
made  for  the  men  to  retreat  into  in  case  of  accident  and  keep  their 
heads  above  water  until  assistance  can  come. 

If,  on  the  other  hand,  the  earth  is  tough  and  regular  instead  of 
being  dug  out  by  miners  the  way  is  cut  automatically  with  a  large 
rotary  cutter.  If  it  is  softer  still  and  too  mushy  to  be  counter- 
balanced by  compressed  air,  then  the  top  of  the  forward  shield  is 
made  very  long,  so  as  to  let  the  mud  cave  in  on  a  long  slant  and 
still  not  fall  from  above.  When  it  gets  to  the  consistency  of  por- 
ridge, as  it  is  at  the  bottom  of  the  Hudson,  it  is  found  possible  to 
force  the  shield  ahead  without  any  digging,  merely  letting  the  mud 
ooze  through  the  partition  doors  and  shovelling  it  into  the  cars.  At 
times  it  was  thought  possible  to  force  ahead  without  opening  the 
doors  at  all — merely  pushing  the  mud  out  of  the  way;  but  this  was 
too  simple  to  be  strictly  according  to  the  rules  of  the  game,  and  the 
obstacle  presented  itself  that  the  extra  weight  of  this  overcrowded 
mud  was  enough  to  lift  or  float  the  whole  tunnel  up  out  of  its 
proper  alignment. 

Again,  in  the  Boston  tunnel,  the  mud  was  so  accommodating  as 
to  stand  up  almost  without  support,  so  that  the  whole  machine  was 
reduced  to  a  simple  steel  arch  on  rollers  without  any  partition  at  all. 

Another  of  the  web-foot  engineer's  problems — to  support  a 
great  weight  on  or  over  mud — would  seem  to  be  simpler  than  the 


EXPOSITION  OF  IDEAS  301 

under- water  tunnel  problem;  and,  up  to  a  certain  limit,  it  is.  If 
the  soil  is  capable  of  holding  only  one  ton  on  each  square  foot,  and  a 
certain  column  is  to  sustain  five  hundred  tons,  all  one  has  to  do  is 
to  spread  out  its  base  by  criss-crossed  steel  beams  and  concrete 
slabs  to  the  extent  of  five  hundred  square  feet — if  one  has  the  room; 
and  if  the  adjoining  columns  are  close  enough  to  it  so  that  their  bases 
touch,  you  have  your  structure  floating  on  one  continuous  slab. 
Nothing  could  be  simpler  or  easier — unless  some  other  man  with  an 
equally  heavy  structure  to  support  comes  to  excavate  a  foundation 
alongside  of  yours,  and  the  mud  runs  out  from  under  you.  I  was 
once  talking  with  a  well-borer  in  Boston  who  put  down  wells, 
elevator-rams,  test  holes  for  engineers,  and  so  on.  He  probably 
knew  more  about  the  underground  condition  of  his  town  than  any 
other  citizen,  "if,"  said  he,  "l  were  ever  called  on  to  lay  siege  to 
Boston,  it  would  not  be  with  guns,  fire,  or  dynamite.  I  should 
simply  sink  a  pit  down  near  the  Post-Office,  where  John  Winthrop's 
spring  still  shows  up,  install  a  big  pump,  and  begin  sucking  out 
the  quicksand.  In  about  two  days  every  large  building  in  town 
would  be  a  wreck."     And  so  it  undoubtedly  would  be. 

This  brings  us  to  the  ancient  expedient  of  pile-driving.  Many 
thousands  of  years  ago  the  more  ingenious  and  weaker  part  of  the 
population  of  central  Europe  maintained  itself  against  the  more 
warlike  and  less  mechanically  skilful  part  by  building  itself  pile 
villages  out  over  the  lakes.  And  the  stumps  of  the  piles  on  which 
Caesar  crossed  over  the  Rhine  are  still  to  be  found,  in  proof  that  his 
luminous  Commentaries  are  not  fiction;  yet,  even  in  this  late  day, 
the  science  is  still  young,  and  every  few  months  bring  forth  an 
improvement  in  the  making  and  driving  of  piles.  In  fact,  so  per- 
verse and  unexpected  is  the  behavior  of  piling  that  I  doubt  if  it 
can  ever  be  reduced  to  a  science.  For  instance,  you  may  drive  a 
ninety-foot  pile  into  soft  river  mud  so  easily  that  it  will  fall  of  its 
own  weight  to  a  penetration  of  twenty  or  thirty  feet,  and  go  indefi- 
nitely two  or  three  feet  to  the  blow  of  a  fairly  heavy  hammer;  and, 
having  driven  it,  you  may  immediately  hook  a  line  to  it  and  pull  it 
out  again.  But  allow  it  to  remain  driven  for  an  hour  or  so,  and 
you  may  sink  a  forty-ton  barge  and  break  every  line  in  your  outfit 
trying  to  budge  it.  Similarly  you  may  pound  for  an  hour  on  the 
unfortunate  head  of  a  pile  that  penetrates  quicksand.  A  horse  or 
a  man  could  not  stand  for  a  minute  on  the  spot  without  sinking  out 
of  sight;  yet  the  pile,  as  if  being  driven  on  a  rubber  buffer,  will 


302    COMPOSITION  OF  TECHNICAL  PAPERS 

bounce  stubbornly  under  every  blow,  but  sink  scarcely  a  hair's 
breadth.  Moreover,  having,  in  the  course  of  a  long  and  discourag- 
ing day,  succeeded  in  getting  two  or  three  bents  down  to  a  minimum 
depth,  you  may  return  next  morning  to  see  your  whole  day's  work 
floated  up  and  out  during  the  night  and  idly  sunning  itself  on  a 
sand-bar  a  few  miles  downstream.  Yet  if  you  were  wise  enough  to 
run  a  long  pipe  down  by  the  pile  as  it  was  being  driven,  and  keep  a 
stream  of  water  forced  down  through  it  to  bore  away  the  sand,  you 
would  find,  immediately  on  withdrawing  the  pipe  and  stopping  the 
water,  that  the  pile  was  stuck  fast,  there  to  remain  forever.  No- 
body knows  how  much  a  pile  of  given  length  and  girth  will  bear 
till  he  tries  it;  but  the  holding  power  as  compared  with  any  spread- 
out  surface  footing  is  enormous. 

It  unfortunately  happens,  however,  that  although  a  sound  stick 
of  timber  will  remain  such  in  thoroughly  wet  earth  for  ten  thousand 
years,  it  cannot  be  trusted  to  last  ten  years  in  dry  soil.  Further- 
more, if  it  stand  in  salt  sea  water,  that  harmless-looking  but  very 
costly  long  white  worm,  the  teredo, — which,  although  neither  ugly 
nor  venomous,  wears  a  boring-mill  on  its  head, — will  certainly  make 
short  work  of  it.  Ten  months  in  temperate  water  is  all  he  needs  to 
make  honeycomb  of  the  best  stick  of  pine  that  ever  grew. 

To  prevent  this  destruction  and  decay,  then,  it  is  obviously 
necessary  to  stop  all  timber  work  underground,  below  the  possi- 
bility of  dryness;  and  this  is  what  takes  most  foundation  work  out 
of  the  hands  of  the  top-soil  contractor  and  places  it  in  the  hands  of 
the  web-foot.  There  is  always  some  place  in  New  York,  and  most 
other  large  cities  in  America,  where  he  is  to  be  seen  making  day  and 
night  and  the  neighboring  property  hideous  with  his  smoking, 
pounding  drivers  and  creaking  derricks.  First  you  see  him  taking 
great  pains  to  build  himself  a  water-tight  dam  of  driven  planks  (he 
refers  to  them  as  sheet  piling)  or  steel  staves.  Then  come  his 
bulky  timbers  as  thick  as  a  man's  body,  blocking  the  streets  tem- 
porarily; and  after  these  are  placed,  his  ravenous  bucket  begins  to 
bite  out  the  dirt  from  the  inclosure.  Then  his  driver  pounds  down 
the  piles  that  are  to  do  the  supporting  of  the  piers,  forcing  them 
below  the  water,  and  driving  them  still  farther  with  another  short 
pile  mounted  temporarily  upon  their  vanished  heads.  After  this 
he  has  the  choice  of  pumping  out  the  water  and  sawing  them  off 
evenly,  or  of  rigging  a  buzz-saw  on  a  long  vertical,  revolving  shaft 


EXPOSITION  OF  IDEAS  303 

to  cut  them  off  under  water.  He  has  a  like  choice  in  placing  his 
pier  upon  their  heads.  With  the  water  pumped  away,  he  may  make 
a  dry-land  job  of  it;  or,  leaving  the  water  standing,  he  may  lower 
the  concrete  in  specially  constructed  buckets  that  remain  tight 
until  they  touch  bottom  and  then  accommodatingly  dump  their 
cargoes  without  allowing  them  to  be  washed  away;  or  he  may  drop 
all  the  concrete  down  through  a  steel  or  canvas  pipe  moved  about 
over  the  pile-heads,  or  deposit  it  sewed  up  in  bags.  New  Yorkers 
who  habitually  passed  the  site  will  remember  seeing  these  piling 
and  capping  operations  going  on  to  make  foundations  for  the  then 
heaviest  and  tallest  Park  Row  Building. 

All  these  processes  are  delightfully  simple  to  write  down,  but 
gray  hairs  and  insomnia  lurk  in  their  actual  doing.  I  once  devel- 
oped slight  symptoms  of  this  sort  over  a  project — the  building  of  a 
line  of  piers  through  a  marshland  where  a  railway  crossed  a  slough 
that  promised  some  day  to  be  dredged  out  and  made  navigable 
water.  On  account  of  the  modest  shell-headed  worm,  piles  had  to 
be  cut  off  thirty-five  feet  below  tide — which  meant  about  the  same 
distance  below  ground.  Everything  went  beautifully.  The  sheet 
piling  went  in  like  a  gimlet  into  cheese,  the  big  buckets  ate  up  a  yard 
of  mud  a  minute,  and  the  discharge  water  from  the  pumps  sluiced  it 
out  to  sea.  Everybody  was  happy.  But  when  the  excavation  was 
forty  feet  deep  and  the  pile-driving  began  at  that  level,  all  happiness 
ceased.  The  very  first  pile  that  went  down  penetrated  a  limitless 
reservoir  of  quicksand.  In  an  hour  the  pile  had  become  the  centre 
of  a  funnel-shaped  crater  another  forty  feet  deep  below  the  pit, 
from  which  spouted  up  tons  of  sand  and  water;  and,  in  spite  of  all 
the  pumping  that  could  be  done,  the  big  excavation  that  had 
taken  so  many  weeks  to  dig  was  full  again.  Moreover,  having 
been  undermined  to  the  extent  of  what  flowed  into  the  excava- 
tion, the  entire  surrounding  territory  for  a  radius  of  a  thousand 
feet  began  to  sink.  Down  went  the  trestle  and  the  track;  down 
went  the  big  derrick  and  rolled  over  on  its  side,  steaming  and  sput- 
tering in  the  mud.  Down  went  all  the  sheet  piling  slowly  into  the 
water,  till  the  sea  rolled  in  over  its  top;  but  the  cracking  and  burst- 
ing of  the  great  struts  within  could  still  be  heard  as  the  splinters 
came  floating  to  the  surface.  I  have  never  seen  a  more  dishearten- 
ing wreck.  It  seems  to  me  the  imagination  can  never  grasp  the 
meaning  of  such  a  phrase,  for  instance,  as  "one  hundred  tons," 
nor  grasp  the  immensity  of  the  powers  of  earth  and  water,  till  he 


304    COMPOSITION  OF  TECHNICAL  PAPERS 

happens  to  upset  their  equilibrium  and  see  them  working  in  ponder- 
ous relentlessness  against  him. 

But  were  the  pier-builders  in  this  instance  discouraged?  Not 
at  all.  They  immediately  despaired  of  making  any  money  on  the 
project,  but  not  at  all  of  finishing  it.  They  diked  off  the  sea,  they 
set  up  and  hosed  off  the  derrick-car,  began  slowly  lowering  the  water 
and  replacing  the  broken  timbers  so  far  as  they  could;  and  then 
allowed  the  pit  to  flood  again.  Then,  with  the  weight  of  the  sea 
water  in  the  pit  to  counterbalance  the  quicksand,  they  dug  blindly 
and  slowly  through  the  water.  The  sand  held;  and  taking  courage 
at  this,  they  began  again  to  drive  piles.  Everybody  watche.d 
breathlessly  the  first  pile  to  see  if  the  sand  would  again  gush  forth; 
but  the  weight  of  the  water  continued  to  hold  it.  So  the  piles  were 
driven  as  the  digging  had  been  done — patiently  and  blindly  through 
water.  Once  the  "follower"  pile  slipped  so  that  the  great  hammer 
struck  down  on  nothing  and  the  tall  driver  fell  in  a  heap  of  kindling- 
wood,  and  the  top  man  was  carried  away  to  the  hospital;  but  they 
rebuilt  and  went  on.  Then  came  the  diver  in  his  helmet  and  leaden 
shoes  to  go  down  and  cut  off  the  piles  at  the  right  level.  This  was 
■  the  most  expensive  process  to  the  builders,  but  the  most  interesting 
to  the  onlookers;  for  to  sit  on  the  dike  and  watch  the  long  pile- 
heads  emerge  miraculously  from  the  deep  and  leap  like  porpoises 
in  the  air  was  more  fun  than  a  cock-fight.  Finally  came  the  filling 
with  concrete  through  the  long  pipe  until  enough  solid  concrete  had 
been  placed  to  equal  the  weight  of  water.  Then  the  water  could 
safely  be  pumped  out  and  the  worst  was  over. 

This  being  merely  a  sample  of  the  many  difficulties  of  web- 
foot  operations,  it  is  small  wonder  that  many  schemes  are  afoot 
to  make  piles  of  concrete  so  that  they  will  not  have  to  be  cut  off 
at  such  low  levels.  A  look  at  the  advertising  pages  of  any  engineer- 
ing magazine  will  show  that  much  gray  matter  is  being  expended 
now  in  that  direction.  There  are  concrete  piles  that  are  driven  by 
first  driving  a  steel  pile  surrounded  by  a  thin  steel  skin.  The  pile 
is  pulled  out  again,  leaving  the  skin  to  be  filled  with  concrete. 
Others  are  made  by  driving  a  pipe  with  a  steel  point  and  then 
pulling  it  up.  As  it  comes  up,  the  steel  point  opens  like  a  walnut, 
so  that  concrete  can  be  rammed  down  through  it  to  fill  the  hole. 
And  there  are  piles  that  are  moulded  in  boxes  above  ground  and 
driven  like  wooden  ones,  save  that  the  water  is  jetted  down  through 
a  pipe  in  the  middle  of  them.     But  all  these,  have  their  disad- 


EXPOSITION  OF  IDEAS  305 

vantages.  Who  can  say,  when  a  pile  is  made  underground,  that 
it  is  perfect?  Who  can  say,  when  a  pile  is  driven,  that  it  is  not 
cracked?  Who  can  say  why  the  famous  concrete  piles  in  Baltimore 
Bay  are  rotting  at  the  water's  surface?  Concrete  of  the  modern 
reinforced  variety  has  been  the  cause  of  more  bitter  disappointment 
than  any  material  we  use.  It  will  be  difficult  indeed  to  find  a 
substitute  for  that  good  timber  that  Mr.  Pinchot  is  so  anxious  for 
us  to  save,  and  that,  when  properly  placed,  will  remain  sound  after 
steel  is  rusted,  and  concrete  is  crumbled,  and  gold  itself  is  tarnished. 

It  will  easily  be  seen  that  piling  of  any  sort  has  its  limitations. 
Supposing  the  Boston  well-borer  to  be  correct,  then,  if  such  a  pit 
as  we*  have  described  were  dug  in  any  city,  obviously  the  whole 
neighborhood  would  fall  into  it  were  it  not  based  on  unyielding 
ground. 

Foreseeing  this  possibility  and  its  consequences,  Mr.  F.  H. 
Kimball  had  the  commendable  obstinacy  to  insist  that  the  founda- 
tions of  the  Manhattan  Life  Building  in  New  York  should  go 
down  to  solid  rock.  Notwithstanding  much  adverse  criticism  at 
the  outset,  his  idea  was  finally  accepted  so  completely  that,  during 
the  following  fifteen  years.  New  York  became  the  greatest  deep- 
foundation  city  in  the  world.  Nowhere  else  do  men  go  dry-shod 
eighty-five  feet  below  water-level  without  intervening  barrier — as 
they  did  under  the  Mutual  Life  Building — and  come  back  to  tell 
about  it.  Nowhere  else  do  caissons  sink  at  the  rate  of  two  feet 
an  hour,  as  they  did  on  the  sites  of  the  North  Trinity  and  United 
States  Realty  buildings.  Nowhere  else  does  one  come  upon  com- 
plete portable  air-compressing  plants  that  will  stand  carting  about 
a  city,  and  when  set  down  are  capable  of  sucking  in,  compressing, 
and  cooling  a  column  of  air  a  foot  square  at  the  rate  of  forty-five 
miles  an  hour.  The  New  England  coast  has  its  six-  and  seven- 
masted  schooners;  but  New  York  is  the  only  known  cruising- 
ground  of  the  four-masted,  four-boomed,  electric-driven,  rapid- 
hoisting,  self-turning,  portable  derrick. 

The  colossal  mistake  by  which  New  York  was  originally  located 
is  now  of  incalculable,  value  to  our  engineering  profession;  the  fact 
that  it  stands  upon  an  island  several  sizes  too  small,  surrounded 
and  partly  overlaid  by  sixty  feet  of  mud,  has  developed  more  real 
engineers  in  America  than  all  the  technical  colleges  that  we  have. 

In  the  caisson,  as  elsewhere  in  engineering, we  find  the  principle 
foolishly  simple,  but  the  exigencies  by  the  way  both  dangerous 


3o6    COMPOSITION  OF  TECHNICAL  PAPERS 

and  difficult.  Imagine  a  circular  steel  chimney,  having  two 
air-tight  dampers  in  the  middle  of  it,  to  be  stood  on  end  in  soft 
ground.  Obviously  its  weight,  resting  on  its  thin  edge,  would  force 
it  down  like  a  pastry-cutter  through  dough.  If,  then,  a  man 
got  into  its  interior  and  began  digging  and  passing  out  the  dirt 
in  buckets  or  sacks,  he  could  continue  to  lower  the  earth  level 
inside  and  the  chimney  would  continue  to  sink;  but  after  three 
or  four  feet  the  water,  which  he  could  not  remove  faster  than  it 
ran  in,  would  bring  hira  to  a  halt.  Now,  a  column  or  a  stick 
of  water  an  inch  square  and  a  foot  high  weighs  about  half  a  pound. 
Therefore,  if  air  were  pumped  into  the  chimney  below  the  dampers 
until  it  pressed  half  a  pound  on  every  square  inch  of  it,  the  water 
would  subside  one  foot;  if  five  pounds,  ten  feet;  if  fifty  pounds, 
one  hundred  feet,  and  so  on.  The  earth  could  be  passed  or  hoisted 
out  past  the  dampers  without  allowing  the  air  to  escape,  just  as  a 
boat  passes  through  a  canal  lock  without  wasting  more  than  the 
lockful  of  water.  But  the  unfortunate  "sandhog,"  the  crouching, 
sweating  digger  of  earth  inside  the  chimney,  is  seldom  found  who 
could  stand  fifty  pounds  of  air  on  every  square  inch  of  him,  inside 
and  out,  and  there  is  the  difficulty. 

There  are  other  difficulties.  Suppose  the  air-pressure  more  than 
counterbalances  the  chimney — the  caisson;  then  tons  of  iron  or 
concrete  must  be  piled  on  it  to  sink  it;  sometimes  it  is  possible  to 
use  the  future  pier  for  this  purpose.  Suppose  the  air  more  than 
balances  the  water  and  blows  out,  causing  a  leak  and  the  sudden 
imprisonment  of  Mr.  Sandhog.  Suppose,  on  the  other  hand,  that 
through  the  breakage  of  a  pipe  or  the  explosion  of  a  cylinder,  it  falls 
below  normal.  There  again  is  danger.  It  is  all  danger,  in  a  way, 
until  the  caisson  is  safely  down  on  hard  rock  and  filled  with  con- 
crete. When  we  arrive  at  a  habitable  structure  like  the  Metro- 
politan Tower,  seven  hundred  feet  high,  standing  ankle-deep  in  sixty 
feet  of  mud,  with  nearly  four  thousand  tons  bearing  on  every  ankle, 
we  see  that  man  is  "monkeying"  with  weights  and  balances  so 
enormous  that  they  outrun  his  imagination.  Mathematics  is  his 
only  medium  for  arriving  at  them. 

More  baffling  still,  the  constitution  and  endurance  of  Mr. 
Sandhog  himself  can  not  be  scientifically  determined.  He  may, 
at  any  moment,  with  the  pressure  of  three  additional  atmospheres 
upon  him  drop  with  heart  failure,  or  be  struck  with  paralysis,  or 
come  out  of  his  caisson,  after  a  brief  hour  and  a  half's  work,  stone- 


EXPOSITION  OF  IDEAS  307 

deaf  for  the  rest  of  his  days.  All  miscalculations,  oversights, 
accidents,  and  blunders  in  this  business  are  payable  in  human 
life.  No  large  undertaking  of  this  sort  is  without  its  tragedy,  and 
one  has  but  to  stop  and  read  the  familiar  little  tablet  on  Brooklyn 
Bridge  to  be  set  thinking  of  the  prices  we  have  to  pay  for  the  things 
we  have  to  have. 

Yet,  notwithstanding  the  difficulties  encountered  by  the  way 
and  the  very  rapid  development  of  his  art,  the  modern  web-foot 
has  carried  on  his  operations  so  scientifically  that  to-day  we  have 
the  astonishing  but  perfectly  sane  statement  of  Mr.  O.  F.  Semsch, 
the  designer  of  the  Singer  Building  frame,  that,  given  a  lot  two 
hundred  feet  square  and  the  trifling  sum  of  $60,000,000,  he  could 
erect  a  building  or  tower  two  thousand  feet  high  which  would 
stand  perfectly  firm  against  sinking  or  blowing  over,  and  be  well 
within  all  the  building  ordinances  of  the  city. 

In  order  to  appreciate  the  great  jump-off  from  ancient  custom 
that  had  to  be  made  in  order  to  accomplish  these  things,  we  need 
take  only  the  most  superficial  glance  at  the  older  structures.  The 
Pyramids  are  securely  founded  on  high  and  dry  rock;  therefore 
above  reproach.  Most  of  the  Roman  edifices  are  also  on  hills. 
The  Tiber,  being  an  intermittent  stream,  enabled  the  Romans  to 
build  a  few  good  bridges  during  dry  seasons;  but  the  Forum,  being 
on  marshland,  is  an  engineering  botch,  and  the  Cloaca  Maxima  so 
persistently  apt  to  get  stopped  up  that  for  hundreds  of  years  the 
whole  works  were  abandoned  and  used  for  a  dump.  Going  a  little 
further,  we  have  the  leaning  towers  of  Pisa  and  Bologna,  not  to 
be  compared  in  weight  to  a  large  modern  factory  chimney,  yet 
able  to  show  us  how  lamentably  weak  the  old  fellows  were  the  min- 
ute they  got  a  bit  bogged;  and  in  Venice  we  see  the  most  striking 
example  of  how  an  entire  city,  although  beautifully  architectured, 
was  never  properly  foundationed. 

The  costly  buildings  of  Chicago,  standing  on  shallow  grillage 
and  sinking  so  many  inches  a  year,  serve  to  emphasize  at  what  a 
late  date  builders  still  hesitated  to  venture  into  the  unstable  depths. 

Considering,  then,  the  courageous  jump-off  from  all  precedent 
and  established  custom  that  the  web-foot  engineer  has  had  to 
make,  it  is  not  surprising  to  find  that  the  "father  of  civil  engi- 
neering" in  modern  times  was  himself  a  pioneer  web-foot.  John 
Rennie  was  originally  a  mill  constructor.  But  when  the  tide 
washed  the  foundations  out  from  under  his  mills  at  Blackfriars 


3o8    COMPOSITION  OF  TECHNICAL  PAPERS 

Bridge,  he  was  forced  into  matters  of  a  larger  sort.  He  earned 
his  title  by  draining  off  that  part  of  England  which  the  appro- 
priately named  River  Ouse  had  made  into  a  hopeless  swamp  (a 
job  that  baffled  even  the  great  Cromwell),  thereby  furnishing 
the  first  and  best  example  of  the  web-foot's  third  problem,  wherein, 
by  a  system  of  dikes  and  ditches,  he  "un- waters"  the  land  and 
renders  it  fit  for  cultivation.  The  magnificent  Waterloo  Bridge 
across  the  Thames  is  also  his  work, — his  monument, — and  when  one 
looks  upon  this  and  the  adjoining  massive  structures,  which  better 
than  anything  else  portray  the  true  solidity  and  grandeur  of  the 
English  people,  it  is  hard  to  believe  that  they  are  all  standing  knee- 
deep  in  river  mud. 

Rennie  has  his  engineering  descendants  in  every  large  modern 
city — in  almost  every  large  project  of  any  kind;  but  especially  are 
they  to  be  found  in  our  tallest,  heaviest  city  of  all — men  far  more 
worthy  to  be  proud  of  than  the  world's  records  they  have  broken, 
or  the  inventions  they  have  made:  Mr.  J.  T.  O'Rourke,  who  pro- 
posed the  first  circular  caisson  and  invented  a  way  to  remove  the 
roof  or  partition  immediately  over  Mr.  Sandhog's  head  so  as  to 
render  the  concrete  pier  one  solid  piece  instead  of  two;  Mr.  John 
W.  Doty  and  Mr.  Daniel  E.  Moran,  who  simplified  it  further, 
making  the  future  concrete  pier  serve  to  sink  itself  and  arranging 
trap  doors  of  such  lightning  action  that  the  bucket  and  its  muddy 
contents  make  a  trip  every  minute;  Mr.  T.  Kennard  Thomson, 
who  designs  the  four-masted  derricks  and  whom  I  suspect  of  having 
everything  to  do  with  the  speed  records  made  in  sinking  caissons; 
Mr.  Alfred  Noble  and  Mr.  Charles  M.  Jacobs,  under  whose  super- 
vision the  East  River  and  North  River  tunnels  were  designed ;  Mr. 
Samuel  Rea,who  passed  upon  all  the  plans,  and  directed  the  entire 
work;  Mr.  E.  W.  Moir,  who  personally  supervised  its  execution;  to 
say  nothing  of  the  assistants  and  resident  engineers — Harrison, 
Brace,  Mason,  Woodward,  Japp,  Manton,  who  * 'slept  on  the 
job,"  worried  over  it,  perspired  over  it,  dreamed  of  it  in  whatever 
sleep  they  were  fortunate  enough  to  get.  It  is  they  whom  I  have 
respectfully  termed  web-foot  engineers,  who  have  transformed  a 
small  river-girt,  rock-backed,  swamp-covered,  scarcely  habitable 
island,  originally  worth  twenty-four  dollars,  into  what  is  now,  in 
some  respects,  the  most  livable,  though  in  other  respects  the  most 
unlivable,  but  at  all  events  the  most  lived  upon,  most  densely 
populated,  richest  spot  under  the  sun. 


EXPOSITION  OF  IDEAS  309 

Interurban  Electric  Traction  Systems;  Alternat- 
ing Current  vs.  Direct  Current^ 

P.  M.  Lincoln 
Engineer,  Westinghouse  Electric  Mfg.  Co.,  Pittsburgh,  Pa. 

[Mr.  Lincoln's  paper  is  a  good  example  of  a  frequent 
type  of  technical  exposition,  the  comparison.  This  type, 
as  in  the  present  article,  usually  takes  the  form  of  an 
argument  in  favor  of  one  side  of  the  two  or  more  pre- 
sented. Expository  elements  to  be  noted  here  are:  (i) 
the  use  of  numbers  and  subtitles  to  mark  the  various 
divisions  of  the  paper;  (2)  the  fairness  with  which  the 
claims  of  the  other  side  are  met  and  the  methods  by  which 
they  are  disposed  of;  and  (3)  the  concrete  presentation 
at  the  end  of  the  paper  of  typical  cases  with  comparative 
series  of  curves  and  tabular  comparisons.  In  reprinting, 
these  curves  and  tables,  together  with  the  comments  on 
them,  have  been  omitted.] 

Practically  all  the  electric  railway  work  in  America  has  been  done 
by  direct  current.  The  alternating  current  traction  system,  al- 
though it  has  received  considerable  attention  from  American 
engineers,  has  not  until  recently  been  favorably  considered  by  them. 
In  Europe,  on  the  other  hand,  the  alternating  current  traction 
problem  has  received  a  large  amount  of  attention.  The  poly- 
phase induction  motor  has  been  developed  by  European  engineers 
for  traction  purposes  and  a  number  of  installations  have  been  made 
in  Europe  with  apparatus  of  this  character.  American  engineers 
have  consistently  refused  to  adopt  the  polyphase  induction  motor 
for  traction  purposes  on  the  ground  that  it  is  not  suitable  for  that 
purpose.     The  principal  reasons  for  this  stand  are  two  in  number. 

First,  the  polyphase  induction  motor  is  inherently  a  constant 
speed  motor  and  therefore  not  adapted  to  traction  purposes.     Con- 

1  A  paper  read  before  the  Electrical  Section  of  the  Canadian  Society  of 
Civil  Engineers.     Reprinted  from  the  Engineering  News  for  December  I7i 
1903  (Vol.  so)  by  permission  of  the  publishers. 
20 


3IO     COMPOSITION  OF  TECHNICAL  PAPERS 

tinual  change  of  speed  is  one  of  the  characteristics  of  traction  work. 
The  direct  current  series  motor  is  peculiarly  adapted  to  this  class 
of  work  because  it  is  inherently  a  variable  speed  motor.  At  one 
definite  speed  the  polyphase  motor  is  an  efficient  machine,  while 
at  all  other  speeds  the  efficiency  cannot  be  greater  than  the  ratio 
of  the  actual  speed  to  the  synchronous  speed.  For  instance,  if 
the  actual  speed  at  which  a  given  induction  motor  is  working  is 
io%  of  its  synchronous  speed,  the  power  utilized  is  at  most  only 
io%  of  the  power  put  in.  In  traction  work  a  large  part  of  the  work 
done  is  necessarily  at  speeds  below  the  maximum  attained,  and 
at  these  lower  speeds  the  maximum  economy  that  can  be  obtained 
from  induction  motors  is  necessarily  small. 

One  expedient  used  by  European  engineers  to  reduce  this  source 
of  loss  is  the  use  of  motors  in  concatenation  or  in  tandem;  that  is, 
the  secondary  of  one  motor  is  fed  into  the  primary  of  another  on 
the  same  car.  If  the  pair  of  motors  thus  ccwicatenated  are  wound 
for  the  same  number  of  poles,  this  expedient  has  the  effect  of  making 
the  synchronous  speed  of  each  of  the  pair  of  concatenated  motors 
half  that  which  it  is  when  not  in  concatenation.  It  is  equivalent 
in  direct  current  practice  to  throwing  two  shunt  motors  in  series. 
Up  to  the  half-speed  point,  therefore,  there  is  a  gain  of  economy  by 
this  arrangement.  By  winding  the  two  concatenated  motors  for 
different  numbers  of  poles,  more  than  one  point  of  maximum 
economy  can  be  secured  between  zero  speed  and  full  speed,  but  this 
arrangement  has  the  disadvantage  of  being  able  to  use  but  one  half 
the  total  motor  capacity  above  half  speed,  while  the  greatest  ex- 
penditure of  energy  takes  place  above  half  speed.  In  order  to  secure 
the  advantage  of  concatenation,  however,  it  is  necessary  to  add 
largely  to  the  weight  of  the  electrical  apparatus.  European  practice 
has  been  to  equip  cars  with  four  motors,  two  main  motors  and  the 
other  two  being  used  only  while  the  car  is  below  half  speed.  Above 
half  speed  these  latter  two  motors  are  running  idle  and  are  doing  no 
useful  work.  The  energy  required  to  take  care  of  the  additional 
weight  is  an  offset  against  the  energy  which  is  saved  by  concatenat- 
ing the  motor.s.  For  long  runs  this  expedient  would  probably  be 
detrimental  since  the  energy  taken  up  to  transport  the  extra  weight 
would  be  more  than  equivalent  to  the  energy  saved  at  the  start. 

The  second  reason  against  the  use  of  polyphase  induction  motors 
for  traction  purposes  is  the  necessity  for  providing  at  least  two 
overhead  conductors.     If  the  track  is  not  used  as  one  of  the  con- 


EXPOSITION  OF  IDEAS  311 

ductors,  then  the  necessity  arises  of  using  at  least  three  overhead 
conductors.  Maintenance  of  insulation  on  such  overhead  con- 
ductors when  they  are  at  high  voltage  is  naturally  a  difficult 
problem,  more  difficult  than  to  maintain  the  insulation  between  a 
single  conductor  and  ground,  as  would  be  the  case  in  the  single  phase 
system. 

American  engineers,  instead  of  endeavoring  to  adapt  the  un- 
suitable induction  motor  to  traction  purposes,  have  devoted  their 
energies  to  the  development  of  a  suitable  alternating  current  motor. 
The  idea  of  using  a  series  motor  operated  by  alternating  current  is 
not  new.  The  only  alternating  current  single  phase  motors  which 
have  speed  and  torque  characteristics  suitable  for  electric  traction 
purposes  are  those  of  the  commutator  type.  In  this  type  of  alter- 
nating current  motor  the  speed  and  torque  characteristics  are  prac- 
tically identical  with  those  characteristics  in  the  direct  current 
series  motor.  Interurban  electric  traction  work,  such  as  exists 
to-day,  was  not  at  that  time  thought  of,  and  this  is,  in  my  opinion, 
the  field  pecuharly  adapted  to  the  alternating  current  traction 
system. 

In  considering  the  general  problem  of  electric  traction,  the  ques- 
tion naturally  arises — what  is  gained  by  the  use  of  alternating 
current  over  direct  current?  And  the  converse  of  this  question 
naturally  arises— what  is  it  necessary  to  sacrifice  in  order  to  obtain 
the  benefit  of  alternating  current  traction? 

The  principal  advantages  of  the  alternating  current  electric 
traction  over  the  direct  current  are  as  follows: 

(i)  Limits  to  trolley  voltage  are  removed. 

(2)  Avoidance  of  rheostatic  losses. 

(3)  The  necessity  for  rotary  converter  sub-stations  abolished. 

(4)  Manual  attendance  at  the  sub-stations  done  away  with. 

(5)  Danger  of  electrolysis  by  return  current  avoided. 
To  take  up  these  points  more  in  detail: 

(i)  Voltage  Limit  Removed. — The  greatest  item  of  cost  in  the 
electrical  equipment  of  interurban  traction  systems  as  they  exist 
to-day  is  that  of  secondary  distribution.  This  item  of  cost  is 
usually  between  25%  and  50%  of  the  total  for  electrical  equip- 
ment, and  usually  much  nearer  the  latter  figure  than  the  former. 
A  potential  of  600  volts  at  the  motor  in  a  direct  current  traction 
system  is  practically  the  limit  at  which  present  designers  and  manu- 
facturers are  willing  to  guarantee  their  machines,  except  in  some 


3 1 2  COMPOSITION  OF  TECHNICAL  PAPERS 

special  cases.  This  necessarily  limits  the  voltage  fed  into  the 
secondary  distribution  system  to,  say,  700  as  a  maximum.  The 
consequence  of  this  comparatively  low  voltage  is  naturally  a  high 
cost  for  conductors  of  this  secondary  distribution.  The  alternating 
current  system,  providing  as  it  does  the  possibility  of  greatly 
increasing  the  voltage  of  the  distributing  system,  thus  largely 
cuts  down  its  cost. 

Another  point  which  militates  against  the  use  of  direct  current  is 
the  fact  that  when  large  units  are  used  it  is  difi&cult  to  collect  the 
large  amount  of  current  for  their  operation.  For  this  reason,  as 
well  as  an  advantage  in  cost,  trolley  construction  has  been  largely 
replaced  by  the  third  rail  for  interurban  work.  By  raising  the 
voltage  of  the  secondary  system,  however,  the  current  taken  by  a 
locomotive  may  be  reduced  and  consequently  the  difl&culty  with 
collecting  devices  may  be  made  to  disappear. 

(2)  Rheostatic  Losses  Avoided. — In  the  direct  current  system 
the  voltage  at  the  car  is  practically  constant  and  while  the  counter 
E.M.F.  of  the  motors  is  building  up,  the  excess  voltage  must  be 
taken  up  by  resistance.  At  the  start,  therefore,  a  comparatively 
large  rheostatic  loss  occurs.  With  the  alternating  current  system, 
on  the  other  hand,  the  voltage  at  the  car  may  be  controlled  by 
suitable  means,  and  the  rheostatic  loss  thus  avoided.  When  stops 
are  few  and  consequently  runs  are  long,  the  rheostatic  loss  in  the 
direct  current  system  is  a  small  proportion  of  the  total,  and  there- 
fore under  these  conditions  this  advantage  of  the  alternating  cur- 
rent system  is  not  so  greatly  marked.  With  short  runs,  on  the 
other  hand,  and  consequently  frequent  starts,  the  rheostatic  loss 
with  the  direct  current  system  amounts  to  a  considerably  greater 
proportion  of  the  total  loss  and  the  alternating  current  system 
therefore  has  a  greater  advantage. 

(3)  Necessity  for  Rotary  Converters  Avoided. — The  cost 
of  sub-station  equipment  constitutes  one  of  the  large  items  in  the 
cost  of  the  electrical  equipment  of  an  interurban  road.  In  this 
sub-station  equipment  by  far  the  largest  item  of  cost  is  the  rotary 
converters.  In  the  alternating  current  equipment  the  rotary  con- 
verter has  no  place,  thus  avoiding  not  only  a  large  item  of  cost, 
but  also  one  of  the  largest  items  of  the  loss  of  power. 

(4)  Attendance  at  Sub-stations  Done  Away  With. — The 
direct  current  rotary  being  a  piece  of  revolving  machinery,  of  course 
requires  manual  attendance  at  the  various  sub-stations.    Alter- 


EXPOSITION  OF  IDEAS  313 

nating  current  sub-stations  consist  of  static  transformers  only, 
and  therefore  require  attendance  only  for  the  purpose  of  operating 
the  switches.  Making  the  switching  devices  entirely  automatic 
in  their  operation  avoids  the  necessity  of  attendance  for  this 
purpose.  A  still  further  refinement  is  the  use  of  distant  controlled 
switches  operated  from  a  central  point,  say  the  main  power  house. 
Electrically  operated  switches  have  already  been  developed  to  be 
operated  from  a  distance  of  several  hundred  feet,  and  no  reason 
exists  why  this  distance  of  operation  cannot  be  extended  to  20 
or  30  miles  by  proper  design.  By  including  in  such  a  switch-operat- 
ing mechanism  also  a  signaling  device,  by  which  the  position  of  the 
switch  is  made  known  at  the  central  point,  the  switch-operating 
system  becomes  complete  and  no  necessity  exists  for  attendance  at 
the  alternating  current  sub-stations  for  any  purpose  except  occa- 
sional inspection.  There  is,  of  course,  an  expense  in  connection 
with  installing  such  a  system  of  operating  switches  electrically, 
but  it  bears  no  comparison  to  the  expense  of  manual  attendance. 

(5)  Electrolysis, — Electrolysis  of  parallel  conducting  systems 
is  generally  recognized  as  one  of  the  most  serious  dangers  in  con- 
nection with  present  direct  current  trolley  systems,  and  the  fact 
that  an  alternating  current  system  avoids  this  danger  entirely  need 
only  be  mentioned  in  order  to  be  recognized  as  a  marked  advantage. 

So  much  for  the  advantages  which  accrue  to  the  alternating 
current  system.  Now  the  question  arises — what  points  must  be 
sacrificed  in  order  to  obtain  these  advantages?  The  disadvantages 
which  necessarily  accompany  the  use  of  the  alternating  current 
system  traction  system  are  as  follows: 

(i)  Additional  weight. 

(2)  Difficulty  of  operating  on  existing  lines. 

(3)  Increased  rail  loss. 

(4)  The  fact  that  an  active  E.M.F.  exists  between  field  turns. 

(5)  Possible  interference  with  telephones. 
We  will  take  up  the  above  points  in  detail. 

(i)  Additional  Weight. — An  alternating  current  motor  of  a 
given  capacity  is  necessarily  somewhat  heavier  and  somewhat  more 
expensive  than  a  direct  current  motor  for  the  same  capacity.  This 
difference  in  the  motor,  however,  does  not  constitute  the  total 
difference  in  weights  of  equipment.  In  order  to  make  use  of  the 
advantages  of  high  trolley  voltage,  the  alternating  current  equip- 
ment should  preferably  be  provided  with  a  step-down  transformer 


314    COMPOSITION  OF  TECHNICAL  PAPERS 

on  the  car.  Also,  in  order  to  obtain  the  advantage  of  avoiding  the 
rheostatic  losses,  some  provision  must  be  made  for  controlling  the 
voltage  on  the  car.  The  transformer,  the  voltage  control  apparatus, 
and  the  greater  weight  of  motors  make  the  alternating  current 
equipment  necessarily  heavier  than  the  direct  current. 

One  of  the  most  attractive  methods  for  controlling  the  voltage 
on  the  motors  is  the  use  of  an  induction  regulator.  The  principal 
advantage  over  other  forms  is  that  it  does  not  require  the  interrup- 
tion of  the  current  and  is  therefore  of  particular  advantage  in  large 
equipments.  It  is  this  problem  of  breaking  the  current  that  forms 
not  only  the  greatest  difl&culty  with  direct  current  equipments  of 
large  capacity,  but  also  one  of  the  largest  items  in  the  deterioration 
account.  The  induction  regulator  has  the  disadvantage  of  adding 
considerably  to  the  weight  and  in  equipments  of  comparatively 
small  size  where  the  difficulty  of  current  interruption  is  not  great 
will  probably  be  replaced  by  some  other  method  of  voltage  control, 
such  as  loops  or  commutated  coils  on  the  step-down  car  transform- 
ers. 

(2)  Difficulty  of  Operating  on  Existing  Lines. — Practically 
all  interurban  roads  run  in  and  through  cities  on  existing  tracks, 
and  therefore,  must  use  the  existing  sources  of  direct  current  power. 
In  order  to  meet  this  condition  the  equipment  for  an  alternating 
current  interurban  road  must  be  so  arranged  as  to  operate  on 
alternating  current  outside  the  city  and  on  direct  current  inside. 
Although  this  is  entirely  possible,  it  must  necessarily  prove  to  be  a 
matter  of  considerable  complication.  It  means  in  the  first  place 
the  use  of  motors  which  can  be  operated  from  both  direct  and 
alternating  current.  This  is  entirely  possible  with  the  series 
alternating  current  motor.  It  means  in  the  second  place  that 
another  system  of  control  must  be  added  to  the  car.  This  objec- 
tion might  in  part  be  avoided  by  using  rheostatic  control  for  both 
the  alternating  current  and  direct  current  conditions,  but  the 
objection  obtains  that  this  method  will  deprive  the  alternating 
current  system  of  its  advantage  of  saving  rheostatic  losses.  Fur- 
ther, means  will  have  to  be  provided  for  disconnecting  all  trans- 
formers when  running  from  direct  current  system  and  reconnecting 
them  when  running  from  alternating  current  system.  All  these 
matters,  although  they  mean  a  considerable  amount  of  complica- 
tion, are  entirely  possible.     The  most  important  part  of  the  equip- 


EXPOSITION  OF  IDEAS  315 

ment — the  motors — can  be  operated  from  direct  as  well  as  alternat- 
ing current. 

(3)  Increased  Rail  Cost. — Experiments  have  shown  that  with 
alternating  current  from  2,000  to  3,000  alternations,  the  actual  loss 
which  takes  place  with  a  given  current  through  the  iron  rails  is 
from  three  to  five  times  that  which  the  same  direct  current  would 
give.  The  higher  ratios  of  loss  hold  for  the  higher  frequencies. 
At  first  thought  this  seems  to  be  an  important  objection  to  the 
A.C.  system.  But  when  it  is  considered  that  in  order  to  utilize 
the  main  benefit  of  the  alternating  current,  a  higher  trolley  voltage 
is  used  and,  therefore,  smaller  currents  in  the  return  conductor, 
the  element  of  rail  loss  in  an  alternating  current  proposition  may  be 
made  even  a  smaller  proportion  of  the  total  than  in  the  direct  cur- 
rent in  spite  of  the  apparently  large  handicap.  The  rail  loss  with 
direct  current  is  usually  a  small  proportion  of  the  total  and  this  with 
alternating  current,  at  the  trolley  voltages  which  are  usually  con- 
sidered— viz.:  2,000  to  5,000 — becomes  a  much  smaller  proportion. 

(4)  Active  E.M.F.  Between  Field  Turns. — The  space  that 
can  be  assigned  to  the  motor  for  operating  a  car  is  necessarily 
limited.  It  is  this  limitation  of  space,  in  fact,  which  often  forces 
the  use  of  a  four-motor  equipment  instead  of  a  two-motor  equip- 
ment, the  available  space  not  being  large  enough  to  allow  the  in- 
stallation of  motors  two  of  which  are  sufficient  for  the  work. 
When  we  consider  the  A.C.  motor,  the  question  of  space  available 
becomes  still  more  exacting,  first  because  the  A.C.  motor  is  neces- 
sarily heavier  and  therefore  occupies  more  space  than  an  equivalent 
D.C.  motor;  and  second,  because  of  the  active  E.M.F.  that  exists 
between  the  field  turns  in  the  A.C.  motor,  and  which,  other  things 
being  equal,  again  requires  additional  space  for  insulation.  In 
the  matter  of  E.M.F.  between  field  turns,  the  A.C.  and  D.C. 
motors  are  quite  different.  The  E.M.F.  between^the  field  turns  of  a 
D.C.  motor  is  due  simply  to  ohmic  resistance,  and  a  short  circuit 
between  turns  simply  throws  out  of  action  the  turns  so  short  cir- 
cuited, and  if  not  too  severe,  does  not  interfere  seriously  with  the 
motor's  operation.  Between  field  turns  of  the  A.C.  motor,  on  the 
other  hand,  there  is  an  active  E.M.F.  similar  to  that  between  the 
turns  of  a  transformer  winding.  A  short  circuit  between  field  turns 
in  an  A.C.  motor,  therefore,  means  a  destructive  short  circuit  and 
an  immediate  interruption  of  service  from  that  motor.  In  other 
words,  the  effect  of  a  short  circuit  between  the  field  turns  in  an 


3 1 6     COMPOSITION  OF  TECHNICAL  PAPERS 

A.C.  motor  has  the  same  effect  that  a  short  circuit  between  arma- 
ture turns  would  have  in  either  the  A.C.  or  D.C.  motors.  Roasting 
out  of  field  coils  is  one  of  the  most  frequent  causes  of  trouble  in 
D.C.  motor  equipments,  and  it  is  readily  realized  that  this  matter  of 
active  E.M.F.  between  field  turns  in  the  A.C.  motor  is  a  serious  one. 
As  an  offset  against  this  disadvantage  of  an  active  E.M.F.  between 
field  turns,  the  A.C.  motor  possesses  the  advantage  of  being  capable 
of  operation  at  low  voltage,  thereby  reducing  the  number  of  turns 
on  the  series  field  and  increasing  the  proportionate  space  for  in- 
sulation. The  use  of  a  step-down  transformer  on  the  car  makes 
available  any  desired  voltage  at  the  motor.  This  existence  of  an 
active  E.M.F.  between  field  turns  is  the  most  serious  obstacle  to 
the  use  of  high  voltage  on  the  motor.  Even  with  low  voltage, 
the  A.C.  motor  is  laboring  against  the  handicap  of  occupying  more 
space  than  an  equivalent  D.C.  motor,  and  the  use  of  high  voltage 
still  further  increases  this  handicap.  The  limitations  of  space  do 
not  apply  to  the  transformer  in  anything  like  the  same  degree 
that  they  do  to  the  motor,  and  no  particular  diflSculty  is  anticipated 
in  building  a  transformer  for  this  work. 

This  limitation  of  available  space  for  the  motor  and  the  existence 
of  an  active  E.M.F.  between  the  field  turns  make  it  seem  probable 
to  the  writer  that  the  A.C.  railway  motor  of  the  future  will  be 
operated  at  low  voltage  and  will  receive  its  current  from  a  trans- 
former situated  on  the  car. 

(5)  Interference  with  Telephones. — It  is  a  question  whether 
alternating  current  in  the  rails  will  interfere  with  telephones  and 
similar  instruments  more  than  the  direct  current  which  they  have 
to  contend  with  at  present.  In  any  event,  the  amount  of  current  in 
the  rails  can  be  reduced  by  the  use  of  higher  voltages  so  that  this 
source  of  interference  can  be  made  less  than  it  is  with  the  present 
direct  current  system.  Further,  means  have  been  proposed  where- 
by the  current  can  be  confined  entirely  to  separate  conductors 
provided  for  the  purpose  and  not  allowed  to  wander  at  will  through 
any  return  circuit  that  may  exist,  as  is  the  case  with  the  direct 
current  system.  This  can  be  done  of  course  only  at  the  expense 
of  erecting  a  separate  system  for  the  return  currents  and  a  system 
of  series  transformers  whereby  these  currents  can  be  confined  to 
this  return  system.  The  alternating  current  system,  therefore, 
possesses  the  advantage  of  being  able  to  use  the  rails  for  contact 
and  still  not  allowing  the  alternating  currents  to  escape  at  will 


EXPOSITION  OF  IDEAS  317 

through  the  earth.  As  a  matter  of  fact,  interference  with  other 
circuits  by  the  alternating  current  system  is  expected  to  be  less 
than  with  the  present  direct  current  system. 

The  engineer  has  been  defined  as  a  man  who  could  do  for  one 
dollar  what  any  fool  could  do  for  two.  The  engineer,  in  other 
words,  stands  for  efficiency.  It  is  he  who  accomplishes  a  given 
result  with  a  minimum  expenditure  of  effort  and  money.  Suppose 
we  apply  this  criterion  to  the  comparison  between  the  A.C.  and 
D.C.  systems:  by  which  of  these  systems  can  a  given  service  be 
rendered  more  economically?  In  order  to  answer  this  question, 
we  shall  assume  a  certain  typical  interurban  road,  ascertain  the 
first  cost  by  both  systems  and  the  cost  of  operating  by  both 
systems  and  compare  the  results.  Suppose  the  typical  road  which 
we  will  assume  to  be  as  follows: 

Length — 60  miles. 

Schedule  speed — 30  miles  per  hour,  cars  running  half  hour  apart. 

Number  of  stops — 30;  that  is,  typical  run,  2  miles  long. 

Weight  of  D.C.  car  complete,  35  tons. 

Weight  of  A.C.  car  complete,  41.3  tons. 

[Mr.  Lincoln's  paper  concludes  with  two  figures  which  show 
respectively  the  speed-time  and  KW.-hours  curve  of  a  direct- 
current  car  of  35  tons  over  the  typical  run  described,  and  the  same, 
together  with  the  apparent  KW.  and  power  factor,  for  an  alternat- 
ing-current typical  run,  and  an  elaborate  series  of  comparative 
tables  showing  power  consumption,  power  losses,  first  cost,  and 
operating  expenses  for  both  systems,  with  notes  on  this  tabular 
comparison.] 

Telephone  Service  in  America^ 

By  John  J.  Carty,  Chief  Engineer 

American  Telephone  and  Telegraph  Company 

[This  is  an  excellent  example  of  a  type  of  technical 
exposition  frequently  encountered,  the  convention  or 
conference  address  on  a  professional  subject  under  dis- 

1  Privately  printed.  Suggested  by  Mr.  M.  C.  Rorty  of  the  American 
Telephone  and  Telegraph  Company,  and  reprinted  by  generous  permission 
of  Mr.  Carty. 


3i8     COMPOSITION  OF  TECHNICAL  PAPERS 

cussion.  Some  good  things  to  be  noted  about  the  article 
are:  (i)  The  clear  introductory  statement  of  the  aim  and 
scope  of  the  paper;  (2)  the  refusal  of  the  writer  to  accept 
at  their  face  value  the  principal  technical  terms,  automatic 
and  manual,  involved  in  the  discussion,  and  his  clear 
analysis  of  those  terms;  (3)  the  convincing  climactic 
arrangement  of  evidence  against  the  so-called  automatic 
switchboard;  (4)  the  careful  transitions  and  frequent 
division  summaries,  more  necessary  in  an  address  than  in 
a  printed  article;  and  (5)  the  establishment  at  the  conclu- 
sion of  the  writer's  claim  to  a  scientific  judgment  unbiased 
by  selfish  ends.] 

In  the  Discussion  on  Automatic  vs.  Manual  Switchboards 
AT  THE  International  Conference  of  European  Telephone 
and  Telegraph  Administrations  at  The  Sorbonne,  Paris, 
September  4TH  to  iith,  1910,  Mr.  Carty  said: 

Mr.  President  and  Gentlemen: 

In  response  to  your  request  I  shall  speak  upon  the  question  under 
debate.  I  will  tell  of  conditions  in  America,  with  which  I  am  per- 
sonally familiar,  and  regarding  which  I  have  accumulated  data 
covering  a  period  of  years.  I  do  not  presume  to  speak  concerning 
conditions  in  Europe,  so  that  I  shall  be  obliged  if  you  will  regard 
what  I  have  to  say  in  this  light.  From  your  own  expert  knowledge 
of  conditions  in  Europe,  each  of  you  will  be  able  to  judge  how  far 
the  experience  which  we  have  obtained  in  America  may  be  appli- 
cable to  your  own  case. 

The  subject  under  discussion  is  sometimes  stated  as  "The 
Manual  Switchboard  System  versus  the  Automatic  Switchboard 
System."  It  will  be  instructive  to  see  what  is  meant  by  these  two 
terms. 

The  term  Manual  Switchboard  denotes  a  system  whereby  the 
operation  of  connecting  two  subscribers  together  is  performed  by 
hand,  and  without  the  employment  of  automatic  machinery. 

The  term  Automatic  Switchboard,  on  the  contrary,  denotes  a 
system  whereby  the  two  subscribers  are  connected  together  by 


EXPOSITION  OF  IDEAS  319 

automatic   machinery   and   without   the   employment   of   manual 

labour. 

,     I  shall  ask  you  to  consider  with  me  for  a  few  moments  these  two 

systems. 

Let  us  begin  with  the  so-called  Manual  Switchboard  and  make 
a  brief  analysis  of  its  method  of  operation,  and  by  so  doing  we  shall 
find  that  it  abounds  in  automatic  features  and  that  in  its  operation 
automatic  labour-saving  machinery  has  been  employed  to  an 
extent  which  is  truly  surprising  to  anyone  who  makes  the  analysis 
for  the  first  time.  You  will  find  that  the  term  Manual  does  not 
correctly  describe  the  system  to  which  it  is  applied,  and  that  the 
so-called  Manual  Switchboard  System  is  partly  Manual  and  partly 
Automatic,  and  you  will  find  that  the  number  of  automatic  opera- 
tions which  take  place  in  making  a  connection  form  a  large  propor- 
tion of  the  total. 

It  would  consume  too  much  of  your  time  if  I  should  describe  in 
detail  each  of  these  operations  which  is  performed  automatically 
and  each  which  is  performed  manually.  I  shall  give  a  brief  outline 
of  them,  and  when  once  your  attention  has  been  drawn  to  this  phase 
of  the  case,  you  will  have  no  difficulty  in  making  the  complete 
analysis  at  your  own  convenience. 

The  subscriber  desiring  to  make  a  call  first  takes  the  telephone 
from  its  hook  and  places  it  to  his  ear.  This  is  a  manual  act,  but 
one  which  is  necessary  in  every  system.  Removing  the  telephone 
automatically  releases  the  hook  which  flies  into  contact  with  several 
springs,  the  result  of  which  is  to  set  in  motion  a  train  of  automatic 
apparatus  closing  the  subscriber's  circuit  at  the  sub-station  thereby 
automatically  actuating  a  relay  at  the  central  office.  This  relay 
having  been  automatically  set  in  operation  lights  a  lamp  before  the 
operator,  who  thereupon  performs  a  manual  act,  inserting  the  plug 
into  the  answering  spring  jack.  This  again  automatically  makes 
connections,  which  accomplish  a  number  of  different  operations, 
such  as  disconnecting  the  line  relay,  and  so  forth.  The  operator 
works  her  listening  key  and  connects  to  the  called-for  subscriber. 
This  causes  a  train  of  automatic  operations  to  take  place,  and  then 
the  subscriber's  bell  is  rung.  He  takes  the  telephone  from  the 
hook,  and  this  automatically  notifies  the  operator  that  he  is  at  the 
telephone. 

The  reverse  of  all  this  takes  place  when  the  disconnection  is 
made.     The  subscribers  hanging  the  telephones  on  their  respective 


320    COMPOSITION  OF  TECHNICAL  PAPERS 

hooks  thus  set  in  motion  a  complex  train  of  automatic  operations, 
whereby  the  operator,  without  listening  in  upon  the  line  or  asking 
the  subscribers  if  they  are  done  talking,  may  determine  at  a  glance 
that  the  conversation  is  finished,  and  by  the  simple  operation  of 
withdrawing  the  plugs  and  allowing  them  to  fall  automatically 
into  their  positions,  mechanism  is  released  which  automatically 
restores  the  lines  to  their  original  condition. 

In  the  handling  of  trunk  calls,  i.e.,  calls  between  the  "A" 
operator  and  "B"  operator  in  the  different  offices,  another  ex- 
tended series  of  automatic  operations  are  intermingled  with  those 
which  are  performed  manually.  In  fact,  a  complete  analysis  of  all 
the  operations  involved  will  show  that  a  very  large  proportion  of 
them  are  performed  automatically.  Thus,  it  will  be  seen  that  not- 
withstanding what  may  be  said  by  the  partisans  of  the  so-called 
Manual  system,  they  have,  by  their  deeds,  acknowledged  that 
there  are  many  advantages  in  automatic  machinery;  in  fact,  if 
we  trace  the  evolution  of  the  Manual  switchboard  as  exemplified 
in  the  modern  Common  Battery  system,  we  shall  find  that  its 
progress  towards  the  present  high  state  of  efficiency  is  marked  by 
the  adoption  of  machinery  to  perform  operations  which,  in  the 
earlier  systems,  were  done  by  hand. 

In  the  old  type  of  Manual  systems,  it  was  necessary  for  the 
subscriber,  in  order  to  signal  the  office,  to  turn  a  crank,  thus  operat- 
ing the  magneto  generator  and  throwing  a  drop  at  the  central  office. 
At  first  it  was  necessary  for  the  operator  to  restore  this  drop  by 
hand.  Then  a  plan  of  automatically  restoring  the  drop  upon 
the  insertion  of  the  plug  by  the  operator  was  adopted.  Finally, 
the  drop  itself  was  removed  and  relays  automatically  controlled 
by  the  subscriber  and  bringing  into  play  at  the  proper  time  electric 
lights,  were  substituted. 

A  study  of  the  growth  from  the  earliest  systems  to  that  at  present 
in  use  shows  in  a  very  interesting  way  that  the  high  efl&ciency  now 
obtained  from  the  Common  Battery  System  is  largely  due  to  the 
adoption  of  automatic  operations.  As  it  will  be  easy  for  anyone 
to  make  this  analysis  for  himself,  I  will  not  pursue  it  further, 
but  enough  has  been  said  to  make  it  clear  that  the  so-called  Manual 
system  is  really  one  composed  of  both  Manual  and  Automatic 
operations.  It  is  partly  manual  and  partly  automatic.  It  is, 
indeed,  a  form  of  semi-automatic. 

Turning  now  to  the  so-called  Automatic  System  and  making 


EXPOSITION  OF  IDEAS  321 

but  a  brief  analysis  of  its  operation,  we  find  that  properly  speak- 
ing, it  is  not  an  automatic  system,  but  only  partly  so,  and  that  with- 
out the  aid  of  human  intelligence  at  the  central  office  and  without 
the  employment  of  operators,  it  has  not  been  possible  to  operate 
it  on  any  substantial  practical  scale.  While  this  is  true  even  in  a 
telephonic  network  with  a  single  central  office,  the  full  force  of  the 
statement  is  not  appreciated  until  we  contemplate  the  so-called 
Automatic  System  as  being  applied  to  a  comprehensive  telephone 
system,  such  as  sooner  or  later  must  grow  up  in  every  country  and 
in  every  city. 

Let  us  consider  the  operations  of  the  Automatic  System  in  the 
elementary  case  of  a  single  central  office.  The  subscriber  desiring 
to  send  a  call  must  take  his  telephone  from  the  hook  and  perform  a 
number  of  manual  operations,  depending  upon  the  character  of  the 
call  he  wishes  to  send.  Then  he  must  press  a  button,  which  if  all 
goes  well,  rings  the  subscriber  desired. 

It  has  been  found  in  practice,  however,  that  this  automatic 
machinery  at  the  central  ofiice  can  be  made  to  give  service  only 
by  the  aid  of  mechanicians  constantly  in  attendance  there.  The 
duty  of  these  mechanicians  is  not  simply  to  make  repairs  and 
remove  faults  in  the  ordinary  sense  of  the  term,  for  they  do  more 
than  this.  They  actually  assist  the  machinery  to  work.  By  the 
most  careful  training,  some  of  them  become  exceedingly  expert, 
so  that  with  a  supersensitive  ear,  they  are  able  to  detect  when  the 
machinery  is  going  wrong.  They  are  equipped  with  portable 
telephones  and  transmitters,  and  when  they  have  reason  to  suspect 
that  the  call  is  not  going  right,  they  listen  in  upon  the  subscriber's 
line,  and  if  the  machinery  has  gone  wrong,  they  ascertain  from 
him  the  number  desired  and  operate  the  machinery  by  hand,  so  as 
to  produce  the  desired  connection. 

The  assistance  which  they  give  requires  them  to  listen  frequently 
to  the  conversation  of  the  subscribers  and  to  give  constant  sur- 
veillance to  the  connections.  This  supervision  is  as  varied  as  the 
character  of  the  faults  encountered. 

These  men,  whose  presence  is  essential  to  the  working  of  the 
system,  are,  in  fact,  "Mechanician  Operators."  In  addition  to 
these,  operators  must  be  employed  for  toll  and  long  distance  work, 
for  answering  subscribers  who  call  for  numbers  which  have  been 
changed,  and  for  performing  those  large  classes  of  service  requiring 
human  intelligence. 


322    COMPOSITION  OF  TECHNICAL  PAPERS 

In  America,  wherever  you  go  into  an  automatic  exchange,  so- 
called,  there  you  will  j&nd  operators  employed  for  these  various 
classes  of  service  which  I  have  mentioned,  and  for  more  which  I 
might  give  in  detail  if  time  permitted.  In  all  of  these  exchanges 
comfortable  operators'  quarters  are  to  be  found,  together  with  the 
usual  provisions  of  lavatories,  retiring  rooms  and  other  conveniences 
which  are  to  be  found  in  the  so-called  Manual  exchanges. 

But  it  is  not  in  the  system  in  its  undeveloped  state  employing 
only  one  central  office  that  the  ISIanual  features  of  the  Automatic 
system  are  to  be  most  clearly  discerned.  In  order  to  see  how  thor- 
oughly misleading  is  the  term  Automatic  Switchboard  as  applied 
to  these  systems,  it  is  necessary  to  contemplate  a  telephone  system 
more  or  less  highly  developed. 

To  do  this  we  must  consider  the  telephone  system  as  a  whole, 
taking  into  account  all  of  the  circumstances  of  the  case,  not  simply 
one,  or  two,  or  three  of  them,  but  the  whole  multitude  of  factors 
which  enter  into  such  a  complex  problem. 

We  must  give  rigorous  attention  to  a  vast  amount  of  data  and 
requirements  pertaining  to  the  traffic  upon  which  the  design  of  the 
system  is  based,  and  we  must  take  carefully  into  account  all  of 
those  important  commercial  circumstances  which  have  such  a 
profound,  though  often  unsuspected  effect  in  broadly  shaping  the 
results. 

It  is  only  after  we  have  done  all  of  these  things  that  we  are  pre- 
pared to  begin  to  design  the  plant  of  the  Telephone  Company  or 
Administration.  This  word  Plant,  which  in  the  English  language 
is  applied  to  the  structure  constituting  the  physical  property  of  the 
Telephone  Company,  is  happily  suggestive  in  connection  with  the 
point  I  wish  to  illustrate,  for  it  brings  to  mind  the  idea  of  growth, 
and  that  in  a  problem  such  as  ours,  in  order  to  attain  successful 
results,  we  must  contemplate  a  plant  or  system  as  it  must  exist  at 
its  different  stages  of  development.  We  are  not  building  something 
which,  as  it  leaves  our  hands  to-day,  is  in  its  final  form.  Each  day, 
each  month,  each  year,  our  plant  is  growing  and  we  must  so  shape 
it,  and  so  add  to  it,  that  as  this  growth  proceeds  it  will  have  the 
highest  efficiency  which  may  be  expected  of  it  at  each  period  of 
time.  And  above  all,  we  must  take  care  that  the  principles  upon 
which  this  growth  is  planned  will  be  such  that  when  the  system  is 
fully  developed,  it  will  be  working  at  its  highest  efficiency. 

Our  view  is  not  comprehensive  if  it  is  confined  to  the  central 


EXPOSITION  OF  IDEAS  323 

office  switchboard  alone.  We  must  always  have  in  mind,  that  while 
this  is  a  vital  part  of  the  system,  it  is  by  no  means  all,  and  that 
considering  the  telephone  investment  as  a  whole,  the  money  invested 
in  central  office  switchboards  is  a  relatively  small  part  of  the  total. 

In  our  American  practice  we  have  for  years  endeavoured,  and  I 
may  say  with  substantial  success,  to  take  this  view  of  the  situation. 
In  my  office  there  is  a  large  sub-department  devoted  to  the  study  of 
the  question  from  the  standpoint  of  subways  and  cables;  another 
for  buildings;  another  for  all  telephone  apparatus,  including  central 
office  switchboards;  another  and  very  large  department  working 
upon  the  traffic  parts  of  the  problem;  one  devoted  to  development 
studies  relating  to  growth  of  population  and  stations  and  kindred 
subjects;  and  still  another  whose  sole  duty  it  is  to  make  fundamental 
plans  based  upon  all  of  these  data  put  together  and  co-ordinated. 

These  fundamental  plans  being  based  upon  all  of  the  factors  in 
the  case  provide  in  outline  for  the  location  and  number  of  the 
underground  ducts  and  cables,  the  location  and  size  of  the  central 
offices,  and  the  size  of  the  central  office  switchboards. 

It  is  obvious  that  if  to  serve  the  needs  of  a  given  locality,  it  is 
necessary  at  the  present  time  to  put  underground  a  single  duct,  it 
would  be  a  mistake  to  limit  our  construction  to  the  immediate  needs 
of  to-day,  provided,  as  is  nearly  always  the  case,  further  growth  is 
to  be  expected.  Some  provision  for  the  future  must  be  made.  How 
many  ducts,  therefore,  we  should  put  down  in  advance  of  the  im- 
mediate needs  is  a  very  important  engineering  and  economic 
problem.  If  but  one  duct  is  put  down  now,  and  another  one  is 
needed  the  following  year,  manifestly  a  waste  of  money  will  be 
incurred,  due  to  removing  the  pavements  and  making  a  new  excava- 
tion the  following  year.  To  provide  for  the  future,  therefore,  by 
adding  duct  by  duct  and  digging  up  the  streets  each  time  a  new 
duct  is  needed,  would  cause  a  great  waste  of  money. 

On  the  other  hand,  to  take  an  extreme  case,  if  a  sufficient  number 
of  ducts  were  put  down  to  provide  for  the  needs  of  100  years  in  the 
future  (even  assuming  we  could  forecast  correctly  for  such  a  long 
period),  another  waste  of  money  would  take  place,  for  the  interest 
and  other  annual  charges  upon  the  construction  which  must  re-, 
main  unproductive  for  so  many  years  would  more  than  ofifset  the 
saving  which  would  be  made  by  avoiding  the  repeated  excavations. 

We  must  choose,  therefore,  in  our  construction,  some  point 
between  these  two  extremes. 


3  24    COMPOSITION  OF  TECHNICAL  PAPERS 

In  the  plans  which  we  have  made  for  New  York  and  for  the  other 
Cities  in  America,  it  has  been  found,  all  things  considered,  most 
economical  when  building  new  subways  to  plan  for  a  period  some- 
where between  15  and  20  years  ahead.  Such  considerations  as  these 
have  guided  us  in  making  fundamental  plans  for  New  York  City, 
which  so  far  as  buildings  and  subways  are  concerned,  are  intended 
to  form  a  general  guide  for  our  construction  work  which  is  to  take 
place  each  year  for  the  next  20  years.  These  plans  are  not  specula- 
tive or  paper  plans,  but  we  express  our  confidence  in  them  by  fol- 
lowing them  in  the  construction  which  we  do  each  year,  putting 
down  not  only  that  which  is  needed  for  to-day,  but  that  which  after 
most  careful  studies,  represents  our  best  judgment  of  what  will 
be  required  during  a  period  of  20  years. 

It  should  not  be  understood,  however,  that  we  can  forecast  with 
precision  the  requirements  for  so  long  a  period  ahead,  but  we  have 
worked  with  these  fundamental  plans  now  for  so  many  years  that 
we  know  that  they  form  a  trustworthy  guide,  provided  that  they 
are  continually  kept  under  review  and  modified  each  year  as  the 
exigencies  of  growth  demand. 

If  it  would  not  take  me  too  far  away  from  the  subject  under 
debate,  I  could  show  to  you  in  many  interesting  ways  the  vast 
sums  of  money  which  we  have  saved  because  of  these  fundamental 
plans  and  how  absolutely  essential  they  are  in  enabling  us  to  expend 
most  economically  the  enormous  sums  of  money  which  we  annually 
put  into  our  plant.  For  example,  our  expenditure  for  new 
construction  during  the  first  six  months  of  191  o  is  more  than 
$21,000,000. 

With  such  plans  before  us  for  a  given  city,  we  are  able  to  study 
the  probable  conditions  of  the  plant  at  each  period  of  its  growth, 
and  with  such  a  guide  we  are  deterred  irom  installing  a  switchboard 
or  other  system,  however  suitable  it  might  seem  to  be  at  the  mo- 
ment, that  would  not  be  capable  of  growing  into  that  form  and  to 
that  magnitude  which  would  be  required  of  it  by  the  conditions 
which  it  must  encounter  before  its  life  has  expired. 

Some  idea  of  these  conditions  at  New  York  so  far  as  they  are 
affected  by  magnitude  may  be  obtained  from  the  following  data. 
The  fundamental  plans  for  that  city,  not  including  the  vast  subur- 
ban region  outside  of  the  municipal  limits  of  Greater  New  York, 
provided  in  1900  for  a  system  of  51,398  telephone  stations,  served 
from  43  central  oflSces,  the  population  of  the  city  being  3,437,000. 


EXPOSITION  OF  IDEAS  325 

In  1910  the  plans  provide  for  376,000  stations,  served  from  52 
central  offices  with  an  estimated  population  of  4,800,000.  In 
1930  the  plans  provide  for  2,142,000  stations  to  be  served  from  109 
central  offices,  with  an  estimated  population  of  8,800,000. 

Without  any  commentary  whatever  these  figures  at  once  put  us 
on  our  guard  against  the  grave  danger  of  assuming,  even  if  the 
so-called  automatic  system  was  suitable  for  a  small  number  of  sub- 
scribers, that  it  would  be  a  proper  thing  to  employ  in  New  York 
or  any  other  city  where  it  is  expected  that  a  proper  development  of 
the  telephone  will  take  place.  This  feeling  of  caution  is  strength- 
ened when  we  consider  that  in  the  neighborhood  of  New  York 
City  there  is  a  vast  suburban  region  intimately  connected  with 
it  telephonically  and  served  by  a  very  great  number  of  central 
offices  connected  by  a  plexus  of  trunk  lines.  But  there  is  more  than 
tliis  which  we  must  take  into  account  when  we  are  studying  this 
automatic  system  as  applied  to  America.  It  is  the  grand  ideal  of 
Mr.  Theodore  N.  Vail,  the  founder  of  the  Telephone  enterprise  in 
America  and  still  its  active  head,  that  we  shall  provide  Universal 
Service.  That  is,  that  each  person,  firm  or  company  in  the  United 
States  that  ought  to  have  a  telephone  shall  be  provided  with  one, 
and  that  any  person  so  provided  wherever  he  may  be  located,  can 
within  a  reasonable  time  be  connected  to  the  telephone  of  any 
other  subscriber  and  talk  satisfactorily. 

This  is  not  a  mere  dream.  We  have  done  solid  continuous  work 
upon  it  for  more  than  thirty  years  and  now  with  rapid  strides  it  is 
proceeding  to  fulfilment.  At  the  present  time  an  enormous  amount 
of  toll  line  business  takes  place  between  New  York  City  and  the 
territory  tributary  to  it  for  30  miles  around.  In  90%  of  this  busi- 
ness the  connection  is  made  in  an  average  of  38  seconds,  and  in  the 
remaining  10%  the  average  is  about  80  seconds.  In  all  of  these 
cases  the  transmission  conditions  are  so  planned  that  the  subscriber 
may  converse  with  ease.  A  local  call  is  accomplished  in  less  time, 
requiring  only  22  seconds  where  but  one  office  is  involved,  and 
slightly  more  between  two  offices. 

These  figures  which  I  have  given  include  the  elapsed  time  from 
the  receipt  at  the  central  office  of  the  subscriber's  signal  on  the 
lamp  until  he  is  connected  with  and  is  talking  to  the  called-for 
subscriber.  But  to  establish  a  universal  service  requires  working 
over  much  greater  distances  than  this. 

We  already  have  an  effective  long-distance  service  through  under- 


326    COMPOSITION  OF  TECHNICAL  PAPERS 

ground  cables  of  the  Pupin  type  from  New  York  to  Philadelphia 
(90  miles)  and  good  talking  with  prompt  connections  is  an  every- 
day matter  between  New  York  and  Boston  (235  miles).  Our  long 
distance  wires  extend  to  Chicago  and  other  more  distant  western 
cities,  and  to  Washington,  Baltimore,  Atlanta  and  other  places  in 
the  far  south.  At  the  present  time  we  are  extending  an  under- 
ground cable  of  the  Pupin  type  from  New  York  to  Washington  (235 
miles)  and  are  making  surveys  and  plans  for  an  extension  from  New 
York  to  Boston.  More  than  this,  by  the  adoption  of  phantom 
loaded  overhead  circuits  between  New  York  and  Chicago,  and  by 
similar  extensions  westward  as  far  as  Omaha  and  thence  to  the 
Rocky  Mountains,  we  expect  by  the  first  of  January  next  to  have 
so  greatly  extended  our  "Long  Distance"  frontier  that  conversation 
may  be  held  between  Denver,  Colo.,  and  New  York  City,  a  distance 
of  2,200  miles. 

I  have  mentioned  these  things  to  give  a  suggestion  of  the  in- 
tricacy and  magnitude  of  the  system  for  which  switchboards  must 
be  provided  and  to  bring  out  strongly  the  point  of  view  from  which 
we  must  judge  the  capabilities  of  this  so-called  automatic  system. 
Our  problem  is  national,  not  parochial — it  is  indeed  even  interna- 
tional as  your  presence  here  to-day  so  eloquently  testifies. 

We  must  provide  for  the  public  a  comprehensive  system  of  which 
switchboards  form  only  a  part;  and  which  shall  be  suitable  not  only 
for  to-day,  and  for  this  year  and  for  the  next,  but  which  shall  be  at 
its  best  obtainable  efficiency  during  each  period  of  its  entire  life. 
These  things  we  must  do  if  we  are  to  avoid  stupendous  blunders 
and  enormous  reconstruction  costs. 

We  must  regard  our  growing  plant  as  the  landscape  architect 
views  the  subject  matter  with  which  he  works.  He  must  plant  his 
trees  and  shrubs  not  with  a  view  to  the  immediate  results,  but  he 
must  have  in  mind  the  space  which  will  be  occupied,  and  the  shape 
and  character  of  his  plantation  as  it  grows  to  maturity.  He  must 
leave  room  for  his  trees  to  grow  and  must  have  in  his  mind  at  the 
beginning  the  total  effect  which  he  desires  to  produce.  So  it  is 
with  us.  We  must  not  install  a  system  because  of  its  fancied  im- 
mediate attractiveness,  if  we  can  discern,  by  looking  into  the 
future,  that  its  growth  must  be  stunted  and  that  it  can  not  survive 
the  cold  winters  of  practice.  We  are  planning  a  magnificent  park 
with  its  groves  of  trees  and  shrubs.  We  are  not  raising  vegetables. 
We  are  planting  avenues  of  oaks,  not  a  bed  of  mushrooms. 


EXPOSITION  OF  IDEAS  327 

It  is  with  such  thoughts  as  these  that  we  have  studied  the  ques- 
tion of  different  types  of  switchboards  in  America,  and  when  thus 
considered,  it  is  surprising  to  see  how  many  of  the  features  of  the 
so-called  automatic  system  fail  to  apply  to  the  conditions  of  prac- 
tice. Among  these  conditions  with  us  is  the  necessity  of  providing 
private  branch  exchange  service.  This  is  done  by  locating  at  the 
subscriber's  premises  a  switchboard  provided  with  trunk  lines 
extending  to  the  central  office  and  with  a  number  of  stations,  some- 
times a  very  large  number,  located  in  different  parts  of  the  sub- 
scriber's premises  and  connected  with  the  P.  B.  Ex.  Some  of  these 
private  branch  exchanges  have  as  many  as  1,200  stations  connected 
with  them.     This  number,  however,  is  exceptional. 

By  means  of  this  private  branch  exchange  system  a  most  satis- 
factory method  of  giving  local  connections  throughout  the  different 
parts  of  the  subscriber's  premises  is  provided  and  from  any  of  these 
stations  by  means  of  trunk  lines  to  the  central  office,  connection 
can  be  had  to  any  other  station  in  the  entire  telephone  system, 
whether  it  be  reached  by  local,  suburban  or  long-distance  trunk 
lines. 

Notwithstanding  the  work  that  has  been  done  and  all  the  claims 
that  have  been  made,  no  practical  way  has  been  discovered  for 
doing  away  with  the  operators  at  these  private  branch  exchanges, 
and  the  outlook  for  a  practical  solution  meeting  all  of  the  plant, 
traffic  and  commercial  requirements  is  so  discouraging  that  at  the 
present  time  the  best  opinion  is  that  nothing  but  failure  in  this 
respect  is  to  be  expected.  It  should  not  be  understood  that  at  each 
of  these  P.  B,  Ex.  switchboards,  there  is  an  operator  solely  devoted 
to  handling  telephone  calls.  While  this  is  the  case  in  the  larger 
installations,  in  the  smaller  ones,  of  which  there  is  a  very  large 
number,  the  switchboard  is  operated  by  a  clerk  or  some  one  who  has 
also  other  duties  to  perform. 

This  P.  B.  Ex.  development  forms  one  of  the  most  satisfactory 
and  irrjportant  features  of  the  telephone  in  America.  Some  idea 
of  its  popularity  and  the  magnitude  which  it  has  attained  and  is 
expected  to  attain  will  be  gathered  from  the  following  figures. 
In  1900,  New  York  City  had  a  total  of  1,050  P.  B.  Ex.  switchboards, 
located  at  subscribers'  premises  and  serving  12,650  stations,  con- 
nected with  them.  In  1910,  there  are  11,960  P.  B.  Ex.  switchboards 
to  which  there  are  connected  162,560  stations.  In  1930,  as  a  result 
of  our  studies  of  this  subject,  we  are  planning  for  88,400  P.  B.  Ex. 


328    COMPOSITION  OF  TECHNICAL  PAPERS 

switchboards,  having  connected  with  them  a  total  of  1,079,000 
stations.  These  figures  have  a  deep  significance.  They  show  that 
in  the  carrying  out  of  plans  upon  which  construction  work  is  now 
being  done,  that  we  shall  reach  a  point  where  more  than  half  of 
the  stations  connected  with  the  New  York  City  system  would 
require  to  be  handled  by  operators,  even  if  automatic  switchboards 
were  installed  at  the  central  ofl5ce.  But  more  operators  than  these 
would  be  required  in  an  automatic  system  applied  to  New  York. 
Large  numbers  of  toll  operators  and  of  long  distance  operators  and 
monitor  operators  and  operators  for  many  other  classes  of  service 
would  be  needed. 

I  have  not  before  me  a  computation  as  to  the  total  number  which 
would  be  required  in  the  system  which  we  are  planning,  but  some 
years  ago  a  careful  study  was  made  with  a  view  to  seeing  how  far 
the  automatic  system  might  be  advantageously  used  in  New  York 
City  at  that  time.  It  was  then  found  that  counting  P.  B.  Ex. 
operators  and  the  central  ofl5ce  operators,  the  so-called  Manual 
svstem  would  require  13,000  operators,  and  that  in  the  so-called 
automatic  system,  leaving  out  of  account  the  "Mechanician 
Operators,"  there  would  be  required  10,000  operators. 

We  have  studied  this  automatic  system,  not  only  in  connection 
with  its  application  to  large  cities,  but  also  when  applied  to  an 
entire  State.  For  this  purpose  a  thorough  study  was  made  of  the 
telephone  system  of  the  State  of  Connecticut.  This  study  was 
made  by  a  large  staff  of  most  competent  engineers  and  consumed 
several  months  in  the  making.  The  result  of  this  was  to  show  that 
at  the  time  the  study  was  made,  if  we  counted  all  of  the  private 
branch  and  other  operators  needed  with  the  Manual  system,  there 
was  a  total  of  892  required.  A  similar  careful  study  showed  that  if 
the  Automatic  system  were  installed  600  operators  would  be 
needed,  not  counting  the  "  Mechanician  Operators." 

All  these  things  show  that  the  Automatic  system,  which  has  so 
many  alluring  features  about  it  when  its  application  to  simple  con- 
ditions is  considered,  becomes  more  and  more  unsuitable  as  the 
plant  grows.  Even  when  the  automatic  system  is  applied  to  the 
simple  case  of  a  single  office  district  we  have  yet  to  find  an  instance 
in  which  the  total  annual  charges  lying  against  it  are  less  than  the 
Manual. 

I  am  aware  that  statements  have  been  made  by  the  partisans  of 
the  automatic  system  purporting  to  show  that  the  annual  charges 


EXPOSITION  OF  IDEAS  329 

on  that  system  are  much  lower  than  on  the  Manual.  We  have 
analysed  the  conditions  of  these  cases  and  found  the  comparison 
was  not  made  upon  a  fair  basis.  Where  these  Automatic  systems 
have  been  installed,  they  have  taken  the  place  of  obsolete  or  ineffi- 
cient Manual  systems  and  the  comparison  has  been  made  between 
an  Automatic  switchboard  of  the  most  efficient  type  known  and  a 
Manual  switchboard  of  a  very  defective  type.  In  some  cases  the 
comparison  has  been  made  between  the  best  type  of  automatic  and 
the  very  poorest  known  type  of  Manual  switchboard.  It  is  not 
surprising,  therefore,  that  from  such  comparisons,  figures  could  be 
obtained  which  would  appear  to  favour  the  automatic.  We  have 
been  at  great  pains  and  expense  to  make  these  comparisons  on  a 
proper  basis  and  in  a  thorough  and  fair  manner. 

We  have  made  studies  in  a  number  of  cities  in  America,  taking 
into  account  the  factors  of  operating  maintenance,  depreciation, 
taxes,  insurance  and  so  forth.  In  every  case  we  found  that  the 
annual  charges  were  in  favour  of  the  so-called  Manual  system. 

I  think  enough  has  been  said  to  show  that  the  Automatic  system 
properly  considered,  does  riot  do  away  with  operators,  does  not 
operate  without  the  constant  surveillance  of  skilled  mechanicians, 
and  that  it  is  in  truth  not  an  Automatic  system  at  all,  but  merely 
one  form  of  Semi-Automatic  system,  of  which  the  so-called  Manual 
is  another. 

By  such  considerations  as  these  we  are  led  to  a  point  from  which 
we  can  approach  our  subject  with  a  mind  freed  from  bias.  By  so 
doing  we  clearly  see  that  we  have  not  to  do  with  a  partisan  con- 
troversy about  Manual  Switch-boards  versus  Automatic  Switch- 
boards. We  have  before  us  a  broad  question  in  telephone  engineer- 
ing, requiring  for  its  solution  a  clear  apprehension  of  a  host  of  sub- 
jects pertaining  to  the  plant,  traffic  and  commercial  activities  of 
the  Company  or  Administration.  It  is  a  grave  mistake  to  regard 
our  problem  as  being  one  for  the  mechanician  only.  It  is  much 
broader  and  deeper  than  this,  involving  important  questions  of 
political  economy. 

Having  stripped  our  question  of  its  verbal  disguise,  we  see  that 
the  two  systems  are  not  so  antagonistic  as  would  at  first  appear. 
They  both  stand  upon  this  common  ground:  Each  recognizes  the 
importance  of  manual  operations  guided  by  human  intelligence; 
each  recognizes  the  importance  of  automatic  machinery;  each  sys- 
tem employs  both  agencies;  each  system  is  semi-automatic. 


330    COMPOSITION  OF  TECHNICAL  PAPERS 

We  are  now  prepared  to  formulate  the  question  anew.  We  see 
that  it  becomes  a  problem  of  dividing  the  total  operations  to  be 
performed,  in  such  a  manner  that  labour  guided  by  human  in- 
telligence shall  be  employed  where  it  is  most  effective,  and  that 
automatic  machinery  shall  be  employed  where  it  is  most  effective. 
Properly  stated,  therefore,  our  question  is  "What  is  the  best  type 
of  Semi-automatic  switchboard?" 

The  so-called  Automatic  system,  as  I  have  shown,  is  found  un- 
suitable for  the  demands  of  a  comprehensive  system.  The  so- 
called  Manual  system  has  been  tested  by  the  most  severe  demands  of 
a  system  composed  of  5,000,000  telephones,  and  it  has  been  found 
to  answer  every  substantial  requirement.  By  its  means  we  are  to- 
day giving  an  excellent  service  and  our  studies  of  the  future  re- 
quirements show  that  if  nothing  better  is  attainable,  we  can,  with 
the  Manual  system,  supply  in  a  satisfactory  manner  all  the  demands 
of  the  public. 

But  it  would  not  do  for  us  to  rest  content  with  this.  We  must 
at  all  times  strive  for  improvements.  These  are  the  traditions  of 
the  American  Telephone  and  Telegraph"  Company,  added  to  which 
are  the  specific  orders  from  President  Vail  frequently  reiterated, 
that  we  must  constantly  seek  for  improvements  so  that  we  may  at 
all  times  when  it  is  reasonable  and  practicable,  place  at  the  disposal 
of  the  public  that  system  which  solid  experience  has  demonstrated 
to  be  the  best. 

Pursuant  to  this  policy  we  have  spent  hundreds  of  thousands  of 
dollars  in  experiments  and  investigations  pertaining  to  this  subject. 

We  have,  after  many  years  of  work,  developed  and  are  now 
installing  at  New  York  for  an  experimental  demonstration,  a  system 
which  is  avowedly  semi-automatic  and  not  disguised  under  another 
name.  The  advocates  of  this  system  contend  that  it  is  a  mistake 
to  place,  as  is  done  in  the  so-called  automatic  systems,  complicated 
automatic  machinery  at  each  sub-station.  (A  sub-station  is  any 
telephone  set  at  the  subscriber's  premises  which  may  be  connected 
to  the  central  office.)  They  favor  the  use  of  a  sub-station  instru- 
ment identical  with  that  employed  in  the  so-called  Manual,  and  they 
assert  that  this  instrument  is  really  much  more  automatic  than 
the  instrument  employed  in  the  so-called  automatic  system  itself. 

We  must  admit  that  there  is  much  force  in  this  statement,  for 
an  analysis  of  the  operation  of  the  two  instruments  shows  that  the 
manual  operations  required  at  the  automatic  station  are  several 


EXPOSITION  OF  IDEAS  331 

times  more  numerous  than  at  the  manual  station.  In  fact  all  of 
the  manual  operations  required  at  the  manual  station  are  also  re- 
quired at  the  automatic  station.  To  these  must  be  added  at  the 
automatic  station  a  number  of  other  manual  acts,  depending  upon 
the  character  of  the  call  to  be  sent. 

It  is  further  asserted  that  the  apparatus  at  the  automatic  sub- 
station is  complicated  to  a  high  degree,  whereas  at  the  Manual 
station  it  consists  of  simple  elements,  and  that  in  consequence  of 
this,  with  the  vast  multiplication  of  stations  which  must  take  place 
in  a  successful  telephone  system,  the  automatic  system  would  be 
placed  at  a  great  disadvantage. 

In  this  semi-automatic  system  about  which  I  am  now  talking,  a 
counterpart  of  the  automatic  apparatus  which  is  required  at  each 
subscriber's  station  in  the  automatic  system,  is  placed  at  the  central 
office.  Thus  one  of  these  pieces  of  apparatus  is  required  for  each 
"A"  operator's  position  instead  of  one  for  each  sub-station  on  the 
subscriber's  premises.  This  greatly  reduces  the  number  of  com- 
plications, and  one  of  them  being  required  for  each  operator's  posi- 
tion only,  much  more  money  is  available  to  be  expended  upon  its 
construction.  Hence  it  can  be  made  with  great  precision  and  so  as 
to  give  much  more  reliable  working.  Furthermore,  these  pieces  of 
apparatus  being  at  the  central  office,  they  are  under  the  constant 
care  of  expert  maintenance  employees,  who  can  instantly  substitute 
a  spare  apparatus  for  one  which  should  become  defective. 

It  is  contended  on  behalf  of  this  semi-automatic  system  that 
the  "A"  operator's  position  (the  "A"  operator  is  the  one  who 
answers  the  subscriber  in  the  first  instance),  is  a  point  at  which 
human  intelligence  is  needed,  because  of  the  numerous  exigencies 
of  the  service.  I  have  carefully  looked  into  this  statement,  and 
I  am  much  impressed  with  the  force  of  the  reasons  given  in  support 
of  it.  While  the  position  of  the  "A"  operator  seems  to  be  one  where 
human  intelligence  is  required,  it  is  not  so  at  the  position  of  the 
"B"' operator  (the  "B"  operator  is  the  one  who  receives  the  trunk 
call  from  an  "A"  operator  at  another  office).  When  the  work  of 
this  "B"  operator  is  analysed  it  will  be  found  theoretically  that  it 
can  all  be  done  by  machinery  and  that  the  work  to  be  performed 
does  not  require  human  intelligence.  Consequently,  in  this  semi- 
automatic system,  all  of  the  "B"  operators  are  eliminated  and 
machines  substituted.  This  very  greatly  reduces  the  total  number 
of  operators  required,  and  if  the  machinery  can  be  made  to  work 


3  3  2    COMPOSITION  OF  TECHNICAL  PAPERS 

satisfactorily,  it  is  believed  that  greater  precision  of  working  will 
be  attained.  This  expectation  is  based  upon  statistics  which  show 
that  a  large  part  of  the  errors  made  at  the  central  ofl5ce  take  place 
between  the  "A"  operator  and  the  "B"  operator. 

As  the  pieces  of  automatic  apparatus  needed  in  the  semi-auto- 
matic system  at  the  "A"  operators'  positions  in  the  central  ofl5ce 
are  relatively  small  in  number,  it  does  not  seriously  increase  the 
total  expense  to  design  and  construct  them  with  the  greatest  care 
and  with  the  best  workmanship,  so  that  the  utmost  degree  of  pre- 
cision may  be  obtained  in  their  working.  On  account  of  the 
enormous  number  of  such  pieces  of  apparatus  which  would  be 
required  if  they  were  distributed  at  the  subscribers'  premises,  one 
for  each  telephone  station  as  is  required  in  the  automatic  system, 
the  same  high  degree  of  design  and  workmanship  cannot  be  applied, 
because  the  costs  would  be  multiplied  exceedingly.  Hence  in 
respect  to  these  vital  parts  of  the  two  systems,  the  automatic  sys- 
tem must  alway  stand  at  a  disadvantage. 

The  result  of  this  has  been  to  produce  for  the  semi-automatic 
system  an  apparatus  operated  by  a  keyboard  similar  to  that  used  on 
the  typewriter.  Working  with  such  a  keyboard,  it  has  been 
experimentally  demonstrated  that  the  "A"  operator  can  handle  a 
very  much  greater  number  of  calls  than  she  could  in  the  so-called 
Manual  system.  This  fact  greatly  reduces  even  the  number  of 
"A"  operators. 

The  advocates  of  this  sytem  contend  that  they  have  made  the 
best  division  of  labour,  the  best  distribution  of  automatic  machin- 
ery, and  that  they  can  attain  a  higher  degree  of  efficiency  and  much 
lower  annual  costs  than  are  attainable  with  either  the  so-called 
Manual  system  or  the  so-called  Automatic  system. 

Engaged  upon  this  study  and  upon  these  experiments  we  have  had 
a  corps  of  capable  engineers  and  experimentalists  working  for 
years,  and  I  feel  warranted  in  attaching  great  weight  to  their 
favorable  expectations. 

Soon  after  my  return  to  America,  I  hope  to  be  present  at  the 
opening  of  the  Semi-automatic  switchboard,  and  until  we  have 
obtained  the  results  of  this  working,  there  is  not  much  more  that 
I  can  profitably  say  upon  the  details  of  the  subject. 

In  conclusion,  the  situation  as  I  view  it,  is  as  follows :  The  so-called 
automatic  system  is  not,  in  fact,  automatic,  it  is  only  partly  so. 
It  has  been  fairly  and  exhaustively  studied  and  found  to  be  unsuitable 


EXPOSITION  OF  IDEAS  333 

for  the  comprehensive  demands  of  our  present  service,  and  more 
and  more  unsuitable  when  considered  with  respect  to  the  demands 
of  the  future. 

The  so-called  Manual  system  has  successfully  withstood  the 
severe  demands  of  a  system  comprehending  5,000,000  telephones 
and  all  of  our  careful  studies  with  respect  to  future  growth  have 
shown  that  if  nothing  better  were  obtainable,  it  would  furnish  to 
us  a  means  whereby  we  could  supply  an  excellent  universal  service 
to  all  the  people  of  the  United  States. 

As  I  have  already  stated,  a  third  system,  frankly  called  a  Semi- 
automatic system,  is  about  to  be  practically  tried.  If  the  expecta- 
tions regarding  it  are  realized,  it  will  be  a  system  more  efficient 
and  more  economical  than  either  the  so-called  Manual  or  the  so- 
called  Automatic. 

Before  leaving  this  subject,  I  wish  to  speak  briefly  upon  one 
point.  It  has  been  said  by  some  that  we  have  not  generally 
adopted  the  so-called  Automatic  system,  because  we  have  been 
deterred  by  the  large  expenditure  of  money  which  would  be  re- 
quired. 

I  shall  promptly  show  you  that  there  is  no  truth  in  this.  The 
history  of  the  telephone  in  America  has  been  that  of  rapid  change 
from  one  system  to  another,  as  soon  as  improvements  have  been 
demonstrated.  Pursuant  to  this  policy,  the  plant  at  New  York  has 
been  constructed  and  reconstructed  three  times.  A  similar  story 
is  to  be  told  of  the  rest  of  the  country.  Our  Company  has  been 
so  conservatively  financed  and  our  Administration  has  been  so 
keen  to  adopt  new  improvements,  that  ample  depreciation  funds 
have  been  accumulated  so  that  just  as  soon  as  it  is  demonstrated 
that  a  better  switchboard  system  is  available,  we  are  prepared  to 
begin  its  installation  and  proceed  with  the  utmost  practicable  speed 
to  make  the  change.  All  of  this  could  be  done  without  the  slight- 
est disturbance  in  our  financial  arrangements. 

While  there  rests  upon  us  the  responsibility  of  adopting  as  soon 
as  it  is  practicable  and  reasonable  to  do  so  that  which  is  best,  there 
is  a  corresponding  and  most  serious  obligation  of  not  throwing 
away  what  has  been  demonstrated  to  be  a  thoroughly  efficient 
system,  without  having  it  conclusively  demonstrated  that  there  is 
something  better.  I  do  not  see  anything  in  the  present  state  of 
affairs  which  need  give  any  Company  or  any  Administration  any 
concern  with  respect  to  the  possibilities  of  a  sudden  change,  for 


334    COMPOSITION  OF  TECHNICAL  PAPERS 

even  if  it  were  demonstrated  that  a  better  system  were  now  avail- 
able, it  would  be  impossible,  taking  into  account  the  manufacturing 
and  engineering  resources  of  all  the  world,  to  make  the  change 
except  in  a  gradual  manner.  We  have  already  had  so  much  expe- 
rience with  such  changes  that  we  know  how  they  must  take  place. 
They  are  accomplished  by  a  process  of  gradual  evolution  and  not 
by  sudden  revolution. 

In  every  Administration  there  are  from  time  to  time  switch- 
boards which  have  been  worked  for  the  full  period  of  their  life. 
These  must  be  replaced  in  any  event,  and  when  such  cases  arise, 
the  new  type  of  switchboard  is  installed.  This  does  not  involve 
the  abandonment  of  apparatus  having  further  usefulness.  There 
are  also  constantly  arising  cases  where  new  installations  must  be 
made.  These  can  be  installed  on  the  new  plan.  Obviously,  this 
does  not  require  that  any  existing  apparatus  be  thrown  away. 
The  manufacturers  and  the  Administration  staffs  would  find  them- 
selves so  fully  occupied  with  this  work  that  they  would  not  for 
some  years  be  able,  even  if  it  were  desirable,  to  disturb  those  central 
offices  in  which  the  switchboards  have  many  more  years  of  life.  It 
will  be  found  that  by  the  time  the  old  switchboards  have  been 
replaced  and  the  new  ones  installed,  those  switchboards  which 
have  had  to  be  removed  in  advance  of  the  expiration  of  their  life 
would  be  few,  and  in  those  cases  the  work  would  not  be  anticipated 
by  a  great  many  years.  Even  where  a  switchboard  is  removed 
before  its  life  has  expired,  this  need  only  be  done  when  it  is  found 
best,  all  things  considered,  to  replace  it  by  a  new  one  rather  than 
to  continue  it  in  service.  There  is  nothing  in  this  situation-which 
demands  a  headlong  rush,  so  without  wasting  any  time,  v^*^  should 
proceed  with  deliberate  care. 

We,  who  are  charged  with  the  great  responsibility  of  rendering 
such  an  important  service  to  the  Public,  cannot  be  justly  criticised 
if  we  refuse  to  be  carried  away  by  the  enthusiasm  of  Manufacturers 
and  Inventors  and  thus  to  be  led  into  a  wholesale  and  probably  dis- 
astrous experimentation  upon  the  public. 

In  America  we  have  pursued  this  subject  for  many  years  with 
the  utmost  diligence.  An  important  practical  demonstration  is 
about  to  be  made.  We  cannot  foretell  the  answer,  but  we  must 
accept  it  whatever  it  may  be. 

I  have  told  some  of  the  things  we  have  done.  It  has  been  our 
constant  aim  to  keep  an  open  mind  and  to  be  free  from  bias.     We 


EXPOSITION  OF  IDEAS  335 

are  seeking  only   the   truth  and  from  that  we  have  nothing  to 
fear. 

The  Origin  of  the  Industrial  System^ 

Charles  Buxton  Going 

[Scores  of  books  and  articles  written  by  engineers  deal 
not  with  physical  laws  and  man's  methods  of  utilizing 
them  but  with  problems  which  seem  to  belong  well 
within  the  provinces  of  the  psychologist,  the  political 
economist,  the  business  man,  and  the  financier.  To  this 
group  belongs  the  following  general  definition  of  Indus-  ( 
trial  engineering.  The  series  of  articles  of  which  this  is 
one  were  modified,  Mr.  Going  says  in  his  Preface,  to  a 
more  general  audience  from  lectures  given  originally  in 
1908-9  under  the  auspices  of  the  Department  of  Mechan- 
ical Engineering  of  Columbia  University.  This  general 
definition  forms  part  of  what  the  author  calls  a  "primary 
triangulation "  of  the  subject.  The  abstract  ideas  with 
which  he  deals  have  been  made  clear  by  the  concreteness 
with  which  they  have  been  presented.  Most  of  the  com- 
parisons and  examples,  it  should  be  observed,  are  such  as 
will  be  readily  understood  and  appreciated  by  engineers.] 

Industrial  engineering  is  the  formulated  science  of  management. 
It  directs  the  efficient  conduct  of  manufacturing,  construction, 
transportation,  or  even  commercial  enterprises — of  any  undertak- 
ing, indeed,  in  which  human  labor  is  directed  to  accomplishing 
any  kind  of  work.  It  is  of  very  recent  origin.  Indeed,  it  is  only 
just  emerging  from  the  formative  period — has  only  just  crystallized, 
so  to  speak,  from  the  solution  in  which  its  elements  have  been  com- 
bining during  the  past  one  or  two  decades.  The  conditions  that 
Jiave  brought  into  being  this  new  applied  science,  this  new  branch 
of  engineering,  grew  out  of  the  rise  and  enormous  expansion  of 
the  manufacturing  system.     This  phenomenon  of  the  evolution  of 

*  Chapter  i  of  Principles  of  Industrial  Engineering  (McGraw-Hill  Book 
Company,  1911).     Reprinted  by  permission  of  the  publishers. 


336    COMPOSITION  OF  TECHNICAL  PAPERS 

a  new  applied  science  is  like  those  that  have  been  witnessed  in 
other  fields  of  human  effort  when  some  great  change,  internal  or 
external,  forced  them  from  a  position  of  very  minor  importance  into 
that  of  a  major  service  to  civilization.  Columbus  could  blow  across 
the  ocean  in  a  caravel  to  an  unknown  landfall;  but  before  a  regular 
packet  service  could  be  run  between  New  York  and  Liverpool 
navigation  must  be  made  a  science.  It  has  drawn  upon  older, 
purer  sciences  for  its  fundamental  data — upon  astronomy,  meter- 
ology  and  hydrography,  and  later  upon  marine  steam  engineering 
and  electricity;  but  out  of  all  these  it  has  fused  a  distinct  body  of 
science  of  its  own,  by  which  new  practitioners  can  be  trained,  by 
which  certainty,  safety  and  efficiency  of  performance  may  be  sub- 
stantially assured. 

Navigation  is  not  jnerely  making  correct  observations  of  the  sun 
and  stars,  of  lights  and  beacons,  of  log  and  lead;  it  is  not  merely 
directing  the  propelling  and  steering  machinery;  it  is  not  merely 
knowledge  of  courses  and  distances;  it  is  not  merely  storm  strategy. 
It  is  the  co-ordination  of  all  these  in  handling  the  equipment 
provided  by  the  marine  engineer  and  naval  architect,  through  the 
work  of  a  crew  of  men. 

In  somewhat  like  manner,  industrial  engineering^  has  drawn 
upon  mechanical  engineering,  upon  economics,  sociology,  psy- 
chology, philosophy,  accountancy,  to  fuse  from  these  older  sciences 
a  distinct  body  of  science  of  its  own.  It  does  not  consist  merely  in 
the  financial  or  commercial  direction,  nor  merely  in  running  the 
power-plant  or  machinery,  nor  merely  in  devising  processes  or 
methods.  It  consists  in  coordinating  all  these  things,  and  others, 
in  the  direction  of  the  work  of  operatives,  using  the  equipment 
provided  by  the  engineer,  machinery  builder,  and  architect. 
"""^  The  cycle  of  operations  which  the  industrial  engineer  directs 
is  this:  Money  is  converted  into  raw  materials  and  labor;  raw 
materials  and  labor  are  converted  into  finished  product  or  services 
of  some  kind;  finished  product,  or  service,  is  converted  back  into 
money.  The  difference  between  the  first  money  and  the  last 
money  is  (in  a  very  broad  sense)  the  gross  profit  of  the  operation. 
Part  of  this  is  absorbed  in  the  intervening  conversions,  or,  in  other 

1  A  systematic  presentation  of  the  field  of  industrial  engineering  from  an 
entirely  different  point  of  view  and  by  a  very  different  method  will  be  found 
in  "Factory  Organization  and  Administration,"  by  Prof.  Hugo  Diemer; 
McGraw-Hill  Book  Co.     [Author's  note.] 


EXPOSITION  OF  IDEAS  337 

words,  in  the  operations  of  purchase,  manufacture,  sale,  and  the 
administration  connected  with  each. 

Now  the  starting  level  (that  is,  the  cost  of  raw  materials  and 
labor)  and  the  final  level  (the  price  obtainable  for  finished  product) 
— these  two  levels  are  generally  fixed  by  competition  and  market 
conditions,  as  surely  and  as  definitely  as  the  differences  in  level 
between  intake  and  tail  race  are  fixed  in  a  water  power.  Hence 
our  profit,  like  the  energy  delivered  at  the  bus  bars,  varies  not  only 
with  the  volume  passing  from  level  to  level,  but  with  the  efficiency 
of  the  conversions  between  these  levels.  In  the  hydro-electric 
power-plant,  the  conversion  losses  are  hydraulic,  mechanical  and 
electrical.  In  any  industrial  enterprise  the  conversion  losses  are 
commercial,  manufacturing,  administrative.  It  is  with  the  effi- 
ciency of  these  latter  conversions  that  industrial  engineering  is 
concerned. 

The  industrial  engineer  may  have  in  his  organization  staff 
many  mechanical  engineers  superintending  special  departments — 
design  or  construction,  or  the  power-plant,  for  instance — while  his 
own  duty  is  to  co-ordinate  all  these  factors,  and  many  more,  for  the 
one  great,  central  purpose  of  efficient  and  economical  production. 
He  is  concerned  not  only  with  the  direction  of  the  great  sources  of 
power  in  nature,  but  with  the  direction  of  these  forces  as  exerted 
by  machinery,  working  upon  materials,  and  operated  by  men- 
It  is  the  inclusion  of  the  economic  and  the  human  elements  es- 
pecially that  differentiates  industrial  engineering  from  the  older 
established  branches  of  the  profession.  To  put  it  in  another 
way:  The  work  of  the  industrial  engineer  not  only  covers  technical 
counsel  and  superintendence  of  the  technical  elements  of  large 
enterprises,  but  extends  also  over  the  management  of  men  and  the 
definition  and  direction  of  policies  in  fields  that  the  financial  or 
commercial  man  has  always  considered  exclusively  his  own. 

In  general,  the  work  of  the  industrial  engineer,  or,  to  use  a  yet 
more  inclusive  term  which  is  coming  into  general  use,  the  efficiency 
engineer,  has  two  phases.  The  first  of  these  is  analytical — we 
might  almost  call  it  passive  to  distinguish  it  from  the  second  phase, 
which  is  synthetic,  creative,  and  most  emphatically  active.  The 
analytical  phase  of  industrial  or  efficiency  engineering  deals  merely 
with  the  things  that  already  exist.  It  examines  into  facts  and 
conditions,  dissects  them,  analyzes  them,  weighs  them,  and  shows 
them  in  a  form  that  increases  our  useful  working  knowrledge  of  the 


338    COMPOSITION  OF  TECHNICAL  PAPERS 

industry  with  which  we  have  to  deal.  To  this  province  of  indus- 
trial engineering  belong  the  collection  and  tabulation  of  statistics 
about  a  business,  the  accurate  determination  and  analysis  of  costs, 
and  the  comparison  of  these  costs  with  established  standards  so 
as  to  determine  whether  or  not  they  are  normal.  To  this  sort  of 
work  Harrington  Emerson  applies  the  term  ''assays,"  speaking  of 
labor  assays,  expense  assays,  etc.,  and  maintaining  (with  good 
reason)  that  the  expert  efficiency  engineer  can  make  determinations 
of  this  sort  as  accurately,  and  compare  them  with  standards  as 
intelligently,  as  an  assayer  can  separate  and  weigh  the  metal  in  an 
ore.  To  this  province  belong  also  such  matters  as  systematic 
inquiry  into  the  means  and  methods  used  for  receiving,  handling, 
and  issuing  materials,  routing  and  transporting  these  materials 
in  process  of  manufacture,  the  general  arrangement  of  the  plant, 
and  the  effect  of  this  arrangement  upon  economy  of  operation. 
To  this  province  belongs,  also,  the  reduction  of  these  data  and 
other  data  to  graphic  form,  by  which  their  influence  and  bearing 
upon  total  result  are  often  made  surprisingly  and  effectively  mani- 
fest. It  is  wonderful  how  much  new  knowledge  a  man  may  gain 
about  even  a  business  with  which  he  thinks  he  is  thoroughly 
familiar  by  plotting  various  sorts  of  data  on  charts  where,  say, 
the  movement  of  materials  back  and  forth,  or  the  rise  of  costs 
under  certain  conditions,  are  translated  immediately  into  visible 
lines  instead  of  being  put  into  the  indirect  and  rather  unimpressive 
form  of  long  descriptions  or  tabular  columns  of  figures. 

The  great  purpose  and  value,  indeed,  of  these  analytical  functions 
of  industrial  engineering  is  that  they  visualize  the  operations  of 
the  business  and  enable  us  to  pick  out  the  weak  spots  and  the  bad 
spots  so  that  we  can  apply  the  right  remedies  and  apply  them  where 
they  are  needed.  They  make  us  apprehend  the  presence  and  the 
relative  importance  of  elements  which  would  otherwise  remain  lost 
in  the  mass,  undetected  by  our  unaided  senses. 

The  second  phase  of  industrial  engineering — the  active,  crea- 
tive and  synthetic  phase, — goes  on  from  this  point  and  effects 
improvements,  devises  new  methods  and  processes,  introduces 
economies,  develops  new  ideas.  Instead  of  merely  telling  us  what 
we  have  been  doing  or  what  we  are  doing,  it  makes  us  do  the  same 
thing  more  economically  or  shows  us  how  to  do  a  new  thing  that 
is  better  than  the  old.  To  this  part  of  works  management  belongs, 
for  example,  the  rearrangement  of  manufacturing  plants,  of  de- 


EXPOSITION  OF  IDEAS  339 

partments,  or  of  operations  so  as  to  simplify  the  process  of  manu- 
facture; the  correction  of  inefficiencies,  whether  of  power,  trans- 
mission, equipment  or  labor;  the  invention  and  application  of  new 
policies  in  management  which  make  the  ideals  and  purposes  of  the 
head  operate  more  directly  upon  the  conduct  of  the  hands;  the 
devising  of  new  wage  systems  by  which,  for  example,  stim^ulus  of 
individual  reward  proportioned  to  output  makes  the  individual 
employee  more  productive. 

-^The  exercise  of  these  functions,  whether  analytical  or  creative, 
by  the  industrial  engineer  or  the  efficiency  engineer,  requires  that 
he  shall  have  technical  knowledge  and  scientific  training,  but  in 
somewhat  different  form  from  the  equipment  of  the  mechanical 
engineer  and  somewhat  differently  exercised. 

Industrial  engineering  deals  with  machinery;  but  not  so  much 
with  its  design,  construction,  or  abstract  economy,  which  are  strictly 
mechanical  considerations,  as  with  selection,  arrangement,  installa- 
tion, operation  and  maintenance,  and  the  influence  which  each 
of  these  points  or  all  of  them  together  may  exert  upon  the  total 
cost  of  the  product  which  that  machinery  turns  out. 

It  deals  with  materials,  but  not  so  much  with  their  mechanical 
and  physical  constants,  which  are  strictly  technical  considerations, 
as  with  their  proper  selection;  their  standardization,  their  custody, 
transportation,  and  manipulation. 

It  deals  very  largely  with  methods;  but  the  methods  with  which 
it  is  particularly  concerned  are  methods  of  performing  work; 
methods  of  securing  high  efficiency  in  the  output  of  machinery  and 
of  men;  methods  of  handling  materials,  and  establishing  the  exact 
connection  between  each  unit  handled  and  the  cost  of  handling; 
methods  of  keeping  track  of  work  in  progress  and  visualizing  the 
result  so  that  the  manager  of  the  works  may  have  a  controlling 
view  of  everything  that  is  going  on;  methods  of  recording  times 
and  costs  so  that  the  efficiency  of  the  performance  may  be  compared 
with  known  standards;  methods  of  detecting  causes  of  low  efficiency 
or  poor  economy  and  applying  the  necessary  remedies. 

It  deals  with  management — that  is,  ^with  the  executive  and 
administrative  direction  of  the  whole  dynamic  organization,  in- 
cluding machinery,  equipment  and  men. 

It  deals  with  men  themselves  and  with  the  influences  which 
stimulate  their  ambition,  enlist  their  cooperation  and  insure  their 
most  effective  work. 


340    COMPOSITION  OF  TECHNICAL  PAPERS 

It  deals  with  markets,  with  the  economic  principles  or  laws 
affecting  them  and  the  mode  of  creating,  enlargmg,  or  controlling 
them. 

The  most  important  elements  of  industrial  engineering  are 
summed  up  in  this  alliterative  list — machinery,  materials,  methods, 
management,  men  and  markets.  And  these  six  elements  are 
interpreted  and  constructed  by  the  aid  of  another  factor  whose 
name  also  begins  with  m — Money.  Money  supplies  the  gage  and 
the  limit  by  which  the  other  factors  are  all  measured  and  adjusted. 
This  of  course  is  true  not  alone  of  industrial  engineering;  the  civil 
engineer,  the  mechanical  engineer,  the  electrical  engineer,  the 
mining  engineer,  each  and  all  must  normally  be  expected  to  make 
money  for  his  employer  or  client.  One  of  the  simplest  principles 
of  the  profession,  but  one  which  the  mere  technician  sometimes 
finds  it  hardest  to  keep  in  mind,  is  that  the  primary  purpose  for 
which  the  engineer  is  usually  engaged  is  to  direct  the  employment 
of  capital  so  that  it  may  pay  back  dividends  to  its  owners.  And 
while  this  is  generally  true  of  all  engineering  employment,  it  is 
most  particularly,  continuously  and  everlastingly  true  of  works 
management.  It  is  much  easier  to  conceive  of  the  civil  engineer 
or  the  mechanical  engineer  being  retained  to  carry  out  some  piece 
of  work  in  which  scientific  accuracy  is  demanded  regardless  of 
cost,  than  it  is  to  conceive  of  a  shop  superintendent  being  directed 
or  even  permitted  to  manufacture  a  line  of  product  regardless  of 
cost. 

It  is  the  ever-present  duty  of  the  industrial  engineer,  of  the 
efficiency  engineer,  to  study  constantly,  and  to  study  constantly 
harder  and  harder,  the  question  of  equivalency  between  the  dollars 
spent  and  the  things  secured.  It  is  not  sufficient,  for  example, 
for  him  to  know  that  a  machine  sold  for  $ioo  costs  $75  to  make. 
This  may  be  a  very  good  profit  and  the  machine  itself  may  be  an 
excellent  one.  There  may  be  vouchers  honestly  connecting  every 
cent  of  the  $75  cost  with  some  actual  item  of  material,  labor,  or 
expense.  Nevertheless,  the  industrial  engineer  must  constantly 
look  back  of  these  figures  to  see  whether  by  some  change  of 
machinery,  some  modification  of  materials,  some  alteration  of 
methods,  some  higher  skill  in  management,  some  stimulus  to  the 
men,  he  can  make  the  machine  cost  less  than  $75  for  its  manu- 
facture, or  can  make  it  a  better  machine  for  the  same  cost,  or 
perhaps  can  do  both. 


EXPOSITION  OF  IDEAS  341 

In  short,  the  industrial  engineer  is  under  unending  and  unre- 
mitting pressure  to  secure  a  true  proportion  between  what  he 
spends  and  what  he  gets.  And  the  proportion  is  never  true  so 
long  as  the  smallest  opportunity  remains  for  getting  more  in 
return  for  what  he  spends,  or  for  spending  less  in  payment  for  what 
he  gets.  The  function  of  the  industrial  engineer  is  to  determine 
with  the  utmost  possible  wisdom  and  insight  whether  and  where 
any  disproportion  between  expenditure  and  return  exists,  to  find 
the  amount  of  the  disproportion,  the  causes  of  such  disproportion, 
and  to  apply  effective  remedies. 

The  forces  causing  this  pressure  for  the  reduction  of  cost  are 
principally  two.  The  older  and  cruder  is  competition.  The 
later  and  larger,  which  in  itself  carries  the  answer  to  competition, 
is  the  effort  toward  efficiency. 

Competition  was  not  created  by  the  manufacturing  system.  It 
existed  from  the  foundation  of  the  world.  But  it  took  on  a  new 
meaning  and  new  activity  when  the  things  began  to  be  made  first 
and  sold  after  (as  they  are  under  the  manufacturing  system) 
instead  of  being  sold  first  and  made  afterward,  as  they  were  under 
the  older  order.  If  you  contract  to  buy  something  which  is  not 
yet  in  existence — a  bridge,  a  house,  a  suit  of  clothes,  or  what  not — 
the  bargain  is  largely  a  matter  of  estimate,  often,  indeed,  a  matter 
of  guess  work,  on  both  sides.  You  have  to  strike  a  mental  balance 
between  the  several  alternatives  presented  and  compare  in  your 
mind  net  results  of  cost,  design,  quality,  certainty  and  prompt- 
ness of  delivery,  personality,  credit,  and  perhaps  many  other 
things,  some  of  them  intangible,  and  some  only  to  be  proved  by  the 
outcome.  The  proposition  that  seems  most  attractive  is  closed; 
the  competing  ones  are  never  carried  out  at  all.  The  buyer  never 
can  tell  with  absolute  certainty  whether  or  not  he  got  the  best  value 
for  his  money;  he  can  only  compare  the  thing  which  has  been 
made  with  what  he  thinks  the  other  things  would  have  been  if 
they  had  been  made.  The  seller  does  not  know  until  everything 
is  over  whether  or  not  he  made  a  profit,  or  how  much.  But  when 
you  sell  things  already  made,  like  lathes  or  high-speed  engines  or 
dynamos,  off  the  sales-room  floor,  the  prospective  buyer  can  make 
the  most  absolute  and  intimate  comparison  between  the  things  and 
their  prices.  He  can  compare  Brown  &  Sharpe  with  Lodge  & 
Shipley,  Harrisburg  with  the  Ball  engine,  Westinghouse  with 
Crocker-Wheeler.     He   can  compare  accurately   design,   quality, 


342    COMPOSITION  OF  TECHNICAL  PAPERS 

cost  before  a  word  or  a  dollar  passes.  The  necessity  for  offering  the 
best  goods  for  the  least  money  and  yet  making  a  fair  profit  becomes 
vital  and  insistent,  and  so  the  knowledge  of  actual  costs  and  the 
ability  to  reduce  costs  becomes  fundamental.  Competition  has 
therefore  been  in  one  way  a  tremendous  force  for  economy  in  manu- 
facturing. And  yet,  by  a  paradox,  in  another  way  competition 
has  been  one  of  the  great  sources  of  waste,  by  causing  duplication 
of  plant,  of  organization,  of  equipment,  of  sales  effort,  and  of  middle- 
men— none  of  which  may  have  any  better  reason  for  existence  than 
someone's  desire  to  share  in  tempting-looking  profits,  but  all  of 
which  must  be  paid  by  the  consumer — all  of  which  become  a  burden 
on  society  at  large. 

le  new  and  ethically  fine  ideal,  therefore,  Is  efficiency — the 
reduction  of  costs  and  the  elimination  of  waste  for  the  primary 
purpose  of  doing  the  thing  as  well  as  it  can  be  done,  and  the  dis- 
tribution of  the  increased  profits  thus  secured  among  producer, 
consumer,  and  employee.  EflSciency  is  a  concept  as  much  finer 
than  competition  as  creation,  conservation,  is  finer  than  warfare. 
It  is  a  philosophy — an  interpretation  of  the  relations  of  things  that 
may  be  applied  not  only  to  industry  but  to  all  life.  Let  me  quote 
a  few  sentences  from  Harrington  Emerson's  "Efficiency  as  a  Basis 
for  Operation  and  Wages:" 

"If  we  could  eliminate  all  the  wastes  due  to  evil,  all  men  would 
be  good;  if  we  could  eliminate  all  the  wastes  due  to  ignorance,  all 
men  would  have  the  benefit  of  supreme  wisdom;  if  we  could  elimi- 
nate all  the  wastes  due  to  laziness  and  misdirected  efforts,  all  men 
would  be  reasonably  and  healthfully  industrious.  It  is  not  im- 
possible that  through  efficiency  standards,  with  efficiency  rewards 
and  penalties,  we  could  in  the  course  of  a  few  generations  crowd 
off  the  sphere  the  inefficient  and  develop  the  efficient,  thus  pro- 
ducing a  nation  of  men  good,  wise  and  industrious,  thus  giving  to 
God  what  is  His,  to  Caesar  what  is  his,  and  to  the  individual  what 
is  his.  The  attainable  standard  becomes  very  high,  the  attainment 
itself  becomes  very  high 

"  Efficiency  is  to  be  attained  not  by  individual  striving,  but  solely 
by  establishing,  from  all  the  accumulated  and  available  wisdom 
of  the  world,  staff-knowledge  standards  for  each  act — by  carrying 
staff  standards  into  effect  through  directing  line  organization, 
through  rewards  for  individual  excellence;  persuading  the  individual 


EXPOSITION  OF  IDEA S  343 

to  accept  staff  standards,   to  accept  line  direction  and  control, 
and  under  this  double  guidance  to  do  his  own  uttermost  best." 

Efficiency,  then,  and  in  consequence  industrial  engineering, 
which  is  the  prosecution  of  efficiency  in  manufacturing,  involves 
much  more  than  mere  technical  considerations  or  technical  know- 
ledge. If  we  consider  the  way  in  which  the  manufacturing  system 
came  into  existence,  we  can  quite  easily  and  clearly  discover  its 
most  important  elements;  we  shall  see  particularly  something  that 
it  is  of  the  utmost  importance  for  us  to  understand,  and  that  is 
that  it  did  not  originate  in  technical  advances  alone,  and  it  has 
never  depended  upon  technical  advances  alone,  but  it  has  been 
influenced  at  least  in  equal  and  perhaps  in  larger  proportion  by 
economic  or  commercial  conditions,  and  by  another  set  of  factors 
which  are  psychological — that  is,  which  have  to  do  with  the 
thoughts  and  purposes  and  emotions  of  men. 

The  point  is  very  important,  because  true  and  stable  industrial 
progress,  whether  for  the  individual,  the  manufacturing  plant  or 
corporation,  or  the  nation  at  large,  depends  upon  a  wise  coordina- 
tion and  balance  between  technical,  commercial,  and  human 
considerations.  It  is  frequently  necessary  in  addressing  a  com-  ' 
mercial  audience  to  emphasize  the  importance  of  the  technical 
element.  Before  a  technical  audience,  on  the  other  hand,  emphasis 
must  often  be  laid  on  the  commercial  and  psychological  factors  that 
in  practical  achievement  must  always  be  interwoven  with  the  i 
technical  factor.  Every  great  industrial  organization  and  every 
great  step  in  industrial  progress  to-day  includes  all  three  elements, 
but  they  will  perhaps  appear  more  distinct  if  we  look  at  the  origin 
and  source  of  the  manufacturing  system,  out  of  which  this  new 
science  of  industry  has  sprung.  The  origin  of  the  manufacturing 
system  was  clearly  enough  the  introduction  of  a  group  of  inven- 
tions that  came  in  close  sequence  about  the  end  of  the  eighteenth 
century  and  beginning  of  the  nineteenth.  These  were  the  steam 
engine,  mechanical  spinning  and  weaving  machinery,  the  steamboat, 
the  locomotive,  and  the  machine-tool.,  It  is  commonly  assumed 
that  the  great  cause  of  the  entire  movement  was  Watt's  improve- 
ment of  the  steam  engine — that  the  industrial  era  which  began  a 
little  more  than  a  century  ago  was,  so  to  speak,  waiting  in  sus- 
pense, in  the  hush  of  things  unborn,  ready  to  leap  into  being  as 
soon  as  the  prime  mover  had  been  perfected  to  a  point  of  practical 
service. 


344    COMPOSITION  OF  TECHNICAL  PAPERS 

This  view  seems  to  be  incomplete.  The  steam  engine  had  been 
discovered,  forgotten,  and  rediscovered,  it  would  be  difficult  to 
say  how  often,  from  the  time  of  Hero  or  earlier  down  to  the  time  of 
Watt — forgotten  and  ignored  because  the  world  had  no  use  for 
it;  the  economic  conditions  were  not  ripe  for  it.  If  there  had  been 
the  same  demand  for  power  to  pump  the  mines  in  England,  the  same 
demand  for  machinery  in  the  textile  industries  of  England,  the 
same  need  for  better  vehicles  to  transport  commercial  products  by 
land  and  by  sea,  in  the  time  of  Papin  or  the  Marquis  of  Worcester 
that  there  was  in  the  time  of  Watt,  I  think  it  is  quite  conceivable 
that  the  inventions  which  made  Watt  famous  would  have  come  a 
full  century  earlier,  and  his  genius  would  have  been  exerted  upon 
a  later  stage  of  the  problem,  as  the  genius  of  Willans  and  Corliss 
and  Parsons  and  Curtis  has  been  within  the  period  of  our  own 
lives. 

I  am  strongly  inclined  to  believe  that  the  world  has  always 
had  something  near  the  quality  and  quantity  of  engineering  talent 
it  has  been  able  to  use.  When  civilization  was  dependent  chiefly 
upon  roads,  aqueducts,  bridges  and  buildings,  it  got  them.  We 
have  never  done  some  of  these  things  better,  technically  speaking, 
than  the  Assyrians,  or  the  Romans,  or  the  architects  of  the  great 
cathedrals  of  the  Middle  Ages;  some,  indeed,  we  perhaps  never  shall 
do  again  as  well.  Newcomen,  Watt,  Arkwright,  Stephenson, 
Bessemer,  applied  genius  to  a  new  sort  of  opportunity,  rather  than 
embodied  in  themselves  a  new  order  of  genius.  They  may  indeed 
have  been  greater  than  other  workers  who  preceded  them,  but  the 
more  important  element  in  their  success  is  that  the  world  was  at 
last  ready  and  waiting  as  it  never  had  been  before  for  the  peculiar 
product  of  genius  they  had  to  ofifer.  This  readiness  that  opened 
the  door  to  their  success  was  due  to  economic  or  commercial  condi- 
tions, not  merely  to  the  technical  invention.  In  its  larger  relations, 
then,  technical  success  depends  upon  commercial  opportunity. 
There  must  be  a  potential  market.  Bessemer  steel  could  not  have 
found  any  welcome  in  the  Stone  Age.  The  typewriter  would  not 
have  succeeded  in  the  Dark  Ages  when  no  one  but  a  few  clerics  could 
read  and  write.  Savages  who  traded  cocoanuts  for  beads  and  brass 
wire  could  afiford  no  encouragement  to  the  manufacturer  of  the 
cash  register  or  the  adding  machine.  It  was  not  because  of 
thermodynamic  inefficiency  that  Hero's  engine  failed  of  adoption. 
On  the  other  hand,  when  the  world  was  ready  for  steam  power  it 


EXPOSITION  OF  IDEAS  345 

accepted  very  gladly  to  begin  with  a  very  crude  machine,  and 
technical  improvement  went  step  by  step  with  larger  practical  util- 
ization, sometimes  leading  and  sometimes  following.  There  must, 
then,  be  a  potential  market  or  application,  or  advance  in  the  applied 
sciences  will  be  limited.  This  is  an  axiom  to  be  placed  alongside 
of  another — that  there  must  be  scientific  study  and  research,  or 
industries  based  upon  the  applications  of  science  will  stagnate  and 
remain  at  a  low  stage  of  efficiency. 

The  second  factor  in  industrial  progress,  then,  is  the  commercial 
factor.  There  must  be  a  potential  market;  but  it  does  not  follow 
from  this  that  technical  progress  is  wholly  subordinate  to  economic 
conditions.  The  inventor  or  the  engineer  is  not  of  necessity  merely 
a  follower  of  progress  in  commerce  or  industry.  Many  of  the  great 
advances  in  applied  science,  or  in  branches  of  industrial  achieve- 
ment perhaps  too  lowly  to  be  called  applied  science,  have  been  made 
by  man,  who  foresaw  not  only  technical  possibilities  but  commercial 
possibilities — who  undertook  not  only  to  perfect  the  invention  but 
to  show  the  world  the  advantage  of  using  it.  I  think  this  was 
substantially  the  case  with  wireless  telegraphy,  with  the  cash 
register  and  typewriter.  Nobody  had  demanded  these  things  be- 
cause nobody  had  thought  of  them,  and  the  productive  act  in 
each  instance  included  not  only  technical  insight  into  the  possibili- 
ties of  doing  the  thing,  but  human  insight  into  the  fact  that  people 
would  appreciate  these  things  and  use  them  if  they  could  be 
furnished  at  or  below  a  certain  cost.  Modern  industrial  methods 
have  shown  us  that  in  many  cases  there  is  no  such  thing  as  a  fixed 
demand  beyond  which  supply  can  not  be  absorbed,  but  that  demand 
is  a  function  of  cost  of  production.  There  may  be  no  demand  at 
all  for  an  article  costing  a  dollar,  but  an  almost  unlimited  demand 
for  the  same  article  if  it  can  be  sold  at  five  cents.  A  large  part  of 
the  work  of  the  production  engineer  lies  in  the  creation  of  methods 
by  which  the  cost  of  production  is  decreased  and  the  volume  of 
production  is  thereby  increased,  with  advantages  to  both  the 
producer  and  the  consumer. 

In  all  these  cases  you  see  that  technical  achievement,  technical 
success,  is  closely  interlocked  with  industrial  or  economic  condi- 
tions, and  with  the  understanding  and  control  of  industrial  or 
economic  influences  and  forces. 

The  third  factor  in  industrial  progress  is  the  psychological 
factor — the  element  contributed  by  the  mental  attitude,  emotions, 


346    COMPOSITION  OF  TECHNICAL  PAPERS 

or  passions  of  men.  I  might  suggest  its  possible  importance  by- 
reminding  you  that  there  were  centuries  in  which  the  inventor 
of  the  steam  engine,  far  from  being  rewarded,  would  have  been 
burned  at  the  stake  as  a  magician.  This  would  not  have  been 
because  the  extraordinary  character  of  the  achievement  was  un- 
recognized, but  because  its  nature  was  misinterpreted.  That 
particular  form  of  expressing  intellectual  dissent  has  gone  out  of 
date.  We  are  much  more  civilized  now,  and  nineteenth-  or 
twentieth-century  inventors  who  are  far  ahead  of  their  times  are 
no  longer  burned;  they  are  merely  allowed  to  starve  to  death; 
while  those  who  are  timely,  but  not  commercially  shrewd,  are 
usually  swindled  by  some  promoter,  who  in  turn  is  frozen  out  by  a 
trust.  In  any  case,  you  see,  the  simple  technician  gets  the  worst 
of  it  industrially,  not  because  his  physical  science  is  weak,  but 
because  his  commercial  and  mental  shrewdness  is  not  correspondingly 
developed. 

Taking  a  larger  view  of  it,  we  shall  see  that  almost  every  im- 
portant advance  in  engineering  progress  is  made  only  after  a  period 
of  pause,  an  interval  following  proof  of  the  technical  achievement, 
following  even  demonstration  of  its  commercial  economy.  We 
might  call  this  the  psychological  lag — the  time  necessary  for  the 
growth  of  human  faith  sufficient  to  energize  an  industrial  move- 
ment. In  the  case  of  the  electric  railway,  or  the  motor  vehicle, 
for  example,  this  lag  was  measured  by  years.  Bessemer  could 
not  convince  the  ironmasters  of  England,  and  had  to  build  his  own 
plant.  Westinghouse,  having  gained  after  much  difficulty  an 
audience  with  the  greatest  railroad  manager  of  that  day,  was  told 
that  this  practical  railroad  man  had  no  time  to  waste  on  a  damn 
fool  who  expected  to  stop  railroad  trains  with  wind.  The  matter 
deserves  emphasis  because  it  is  almost  certain  to  enter  into  the 
individual  experience  of  every  man.  You  will  have  to  make  some- 
one believe  you,  and  believe  in  you,  before  you  can  get  anywhere  or 
do  anything.  When  a  technical  man  has  a  proposition  to  put 
before  an  individual,  or  a  group  of  individuals,  or  society  at  large,  he 
is  very  likely  to  think  that  scientific  demonstration  of  its  technical 
soundness  ought  to  be  convincing.  You  will  find,  however,  that 
men  at  large  will  substantially  ignore  scientific  proof,  and  that  you 
must  add  to  it,  second,  proof  of  the  commercial  or  economic  argu- 
ment, and  third,  that  psychological  force  which  convinces  not  the 
reason,  but  the  emotions.    In  all  industrial  engineering,  which 


EXPOSITION  OF  IDEAS  347 

involves  dealing  with  men,  this  psychological  or  human  element  is 
of  immense,  even  controlling  importance.  The  principles  of  the 
science  are  absolute,  scientific,  eternal.  But  methods,  when  we 
are  dealing  with  men,  must  recognize  the  personal  equation  (which 
is  psychologic)  or  failure  will  follow.  The  differences  between 
the  several  philosophies  of  works  management  as  expressed  in  the 
wage  systems  which  we  are  going  to  consider  later  are  psychological. 
Success  in  handling  men  and  women,  which  is  one  of  the  most  im- 
portant parts  of  the  work  of  the  industrial  engineer,  is  founded  on 
knowledge  of  human  nature,  which  is  psychology. 

The  great  industrial  movement,  then,  with  which  we  have  to  do  is 
triune  in  its  nature,  the  three  chief  elements  being  the  technical 
or  scientific,  the  economic  or  commercial,  and  the  psychological  or 
human.  They  seldom  respond  at  equal  rates  to  the  impetus  of 
advance.  Sometimes  the  technician  pushes  so  far  ahead  that  the 
world  loses  touch  with  what  he  is  doing  and  his  work  lies  long 
unused  until  civilization  catches  up;  sometimes  the  commercial 
tendency  is  unduly  aggressive,  and  discourages  or  impedes  real 
scientific  achievement;  very  often- the  men  most  concerned  with  the 
industrial  activities  go  badly  wrong  in  their  philosophy,  and  get 
disastrously  false  notions  as  to  what  makes  for  real  progress  and 
real  welfare.  More  diflSculties,  perhaps,  come  from  this  cause' 
than  from  any  other. 

To  the  technical  man,  it  is  an  ever-present  duty  to  keep  in  view 
absolute  ideals,  to  seek  every  chance  for  their  advancement,  and 
to  mould  conditions  and  men  so  as  to  obtain  constantly  nearer 
approach  to  these  ideals;  but  in  doing  this  he  must  never  forget  to 
attach  full  weight  to  economic  conditions,  and  he  must  never  allow 
himself  to  ignore  human  nature. 


CHAPTER  IX 
REPORTS 

Introduction 

Engineering  reports  do  not  really  constitute  a  separate 
and  individual  type  of  technical  writing;  they  consist 
rather  of  a  fusion  of  the  types  already  considered,  and 
gain  their  distinctiveness  from  their  aim  and  the  circum- 
stances under  which  they  are  written  rather  than  from 
the  elements  which  compose  them.  They  are,  if  one 
may  borrow  a  name  from  a  type  of  poetry,  technical 
articles  of  occasion ^  written  to  order  for  a  specified  reader 
or  group  of  readers  and  having  as  their  aim  the  supplying 
of  a  definite  body  of  information  on  a  specific  subject, 
with  or  without  recommendations  based  on  the  data 
collected.  Their  types  are  so  various  as  almost  to  defy 
classification;  some  of  the  more  usual  types  follow: 

1.  Information  reports,  which  consist  entirely  or  almost 
entirely  of  a  body  of  selected  data  gathered  by  an  exper- 
ienced observer. 

2.  Recommendation  reports,  in  which  the  important 
elements  are  conclusions  or  recommendations  based  upon 
collected  data  which  may  or  may  not  also  be  presented. 
To  this  class  belong  the  reports,  for  example,  made  by  an 
expert  municipal  or  sanitary  engineer  to  a  city  council. 

3.  Progress  reports  made,  usually  at  regular  intervals, 
upon  a  piece  of  engineering  construction  under  way. 

4.  Research  reports  based  upon  definite  research  work. 

348 


REPORTS  349 

To  this  type  belong,  for  illustration,  most  of  the  reports 
written  by  government  experts  for  publication  in  govern- 
ment bulletins. 

Student  reports  differ  from  professional  reports  as  a 
broomstick  gun  differs  from  a  rifle.  Their  function  is  to 
instruct  the  student  in  the  facts  of  engineering  science 
and  to  train  him  to  observe  intelligently,  think  rationally, 
and  record  his  observations  and  conclusions  accurately 
and  clearly.  The  reader  of  the  student  report,  who  is 
usually  also  the  overseer  of  the  experiment  or  investiga- 
tion reported,  is  not  dependent,  as  is  the  reader  of  a  pro- 
fessional report,  upon  the  data  and  the  conclusions  pre- 
sented by  the  student;  he  is,  in  effect,  the  servant  of  the 
reporter,  paid  to  assist  in  his  training,  and  not,  as  in 
the  case  of  a  professional  report,  a  superior  who  has 
delegated  a  definite  task  to  him.  But  the  mental  and 
moral  elements  which  enter  into  the  task  of  student  report 
writing  are,  nevertheless,  the  same  as  those  which  figure 
in  the  most  complicated  report  of  the  professional  engi- 
neer; and  the  student,  therefore,  who  refuses  to  enter 
seriously  into  this  part  of  his  work  is  deliberately  lessen- 
ing his  chances  of  later  success.  Most  of  the  principles 
of  report  writing  which  follow  apply,  then,  alike  to  stu- 
dent and  professional  reports. 

Fundamental  Qualities 

Engineering  reports,  as  has  been  said,  contain,  or  are 
likely  to  contain,  elements  of  technical  description,  pro- 
cess-exposition, and  exposition  of  ideas.  Any  report, 
therefore,  may  demand  from  the  writer  an  application 
of  the  principles  of  these  forms  of  technical  exposition. 
Since  these  principles  have  already  been  explained  in 


350    COMPOSITION  OF  TECHNICAL  PAPERS 

earlier  chapters,  they  need  not,  however,  be  taken  up 
here.  In  addition,  engineering  reports  make  upon  the 
writer  certain  demands  which  arise  more  or  less  directly 
from  their  peculiar  nature  and  purpose;  and  these  will  be 
discussed  briefly.  Most  of  these  qualities  pertain  rather 
to  the  writer  of  the  report  than  to  the  report  itself,  and 
may  seem,  for  that  reason,  hardly  to  belong  to  the  com- 
positional side  of  report  making;  but  as  their  presence 
results  in  good  reports  and  their  absence  in  bad  ones, 
their  consideration  is  really  justified.  What  follows  is 
merely  an  attempt  to  analyze  and  crystallize  common 
sense  in  report  writing. 

I.  Analysis  of  the  Problem. — Engineering  reports  have 
been  defined  (page  348)  as  "technical  articles  .  .  .  written 
to  order  for  a  specified  reader  or  group  of  readers  and 
having  as  their  aim  the  supplying  of  a  definite  body  of 
information  on  a  specific  subject."  It  will  be  seen,  then, 
that  the  first  task  of  the  report  writer  is  to  make  certain 
that  he  understands  his  problem.  When  a  committee 
appointed  to  make  an  investigation  holds  its  initial  meet- 
ing, the  first  step  taken  is  usually  the  definite  determina- 
tion of  the  things  to  be  investigated  and  reported  upon. ' 
In  the  finished  report  the  specific  limits  of  the  field  of 
investigation  as  the  committee  understands  them  are 
usually  indicated  clearly  in  the  opening  paragraphs. 
Similarly,  an  individual  has  the  task  in  all  but  routine 
reports  of  determining  what  the  limits  of  his  field  are, 
just  what  special  facts  he  is  to  investigate  and  report 
upon,  and  whether  he  is  expected  merely  to  present  data 
or,  in  addition,  to  make  recommendations.  Svch  a  clear 
introductory  analysis  of  his  problem  will  insure  his  con- 
fining his  attention  to  the  details  wanted  by  the  readers 
of  the  report  and  will  prevent  him  from  wandering  into 


REPORTS  351 

fields  beyond  the  limits  of  his  special  investigation.  An 
analysis  of  his  problem  need  not  keep  him  from  present- 
ing, on  the  other  hand,  data  which  will  really  be  useful  to 
the  reader  of  the  report. 

2.  Promptness. — The  student  who  is  refused  credit  for 
a  late  report  sometimes  thinks  that  his  instructor  is  hard- 
hearted. He  does  not  stop  to  consider  that  out  in  the 
world  big  economic  leaks  often  result  from  the  failure  of 
employees  to  furnish  information  at  the  time  when  it  is 
needed.  In  college  when  a  report  is  not  submitted  on 
time,  the  student  alone  is  the  loser;  and  he  is  merely 
warned  or  penalized  by  his  instructor.  In  practice  when 
a  report  is  not  submitted  on  time,  the  work  of  others 
may  be  seriously  interfered  with,  and  the  dilatory  report 
writer  is  at  once  branded  as  unreliable.  In  practice 
social  engagements,  pressure  of  work,  sickness  even, 
must  not  interfere  with  the  task  of  getting  the  data  in  on 
time.  The  following  little  dialogue  between  a  superin- 
tendent and  a  young  engineer  is  typical. 

Superintendent:  *'Mr.  Jackson,  can  you  get  this  in- 
formation for  us  by  noon  of  next  Tuesday?" 

Mr.  Jackson:  *'I'll  do  my  best,  sir." 

Superintendent:  "No;  your  best  will  not  do.  The 
directors  must  have  those  data  by  noon  on  next  Tuesday. 
If  you  can't  get  the  information,  I'll  ask  Mr.  Ray  to  do 
so.     Can  you  do  it?" 

Mr.  Jackson:  "Yes" sir." 

And  Mr.  Jackson,  being  wise,  gets  the  report  in  on 
time. 

3.  Accuracy. — The  training  in  accuracy  of  observing 
and  recording  which  it  is  the  aim  of  student  reports  to 
provide  is  in  practice  one  of  the  most  necessary  of  moral 
qualities.     Incorrect  data  are  worse  than  useless,  for  con- 


352    COMPOSITION  OF  TECHNICAL  PAPERS 

elusions  and  actions  based  upon  them  are,  necessarily, 
also  incorrect.  A  young  engineer  who  through  careless- 
jiess  or  incompetency  constantly  submits  incorrect  in- 
formation is  an  economic  loss  to  his  employers,  and  his 
chances  of  ever  obtaining  any  position  of  responsibility 
are,  therefore,  nil. 

4.  Honesty. — The  writer  of  a  report  should  never  for- 
get that  he  is  not  the  master  but  the  servant  of  the  facts 
which  he  is  gathering.  No  sound  conclusions  can  possi- 
bly be  based  upon  facts  which  have  been  controlled  or 
juggled,  and,  moral  considerations  quite  aside,  it  is  en- 
tirely unscientific  to  fail  to  record  data  exactly  as  they 
are  found.  The  temptation  which  often  comes  to  the 
student  in  the  laboratory  to  warp  the  data  slightly  away 
from  the  truth  in  order  that  a  known  conclusion  may  be 
more  easily  reached  has  its  counterpart  in  the  world  in 
the  temptation  which  comes  to  a  paid  investigator  to 
bend  facts  to  a  desired  conclusion  or  to  manufacture 
evidence  so  that  he  may  secure  results  pleasing  to  his 
employers.  In  college  the  offense  seems  slight  and  in- 
dividual, and  results  too  often  in  only  a  light  penalty. 
In  practice  it  is  often  criminal,  since  it  plays  fast  and  loose 
with  the  well-being  of  society,  and  the  penalties  are 
correspondingly  severe. 

5.  Completeness. — The  writer's  analysis  of  the  problem 
should  not  lead  him  to  omit  elements  needed  in  the  report. 
He  should  be  careful  to  cover  all  points  and  to  include  all 
data  likely  to  be  of  use  to  the  reader.  Failure  to  do  this 
may  result  in  the  necessity  for  supplementary  reports 
and  in  consequent  delay  and  economic  loss. 

6.  Brevity. — As  far  as  is  consistent  with  completeness 
of  information  engineering  reports  should  be  as  brief  as 
possible.     Busy  men  have  little  time  for  anything  but 


REPORTS  353 

the  core  of  the  matter;  they  cannot  usually  wade  through 
elaborate  and  unnecessary  explanations.  The  first 
report  of  a  conscientious  young  engineer,  now  well  ad- 
vanced in  his  profession,  was  six  typewritten  pages 
in  length  and  was  plentifully  decorated  with  drawings 
and  stuffed  with  intricate  mathematical  proofs.  **Uh- 
huh,' '  said  the  superintendent,  as  he  held  one  hand  over 
his  mouth  and  rapidly  turned  the  pages  with  the  other; 
"  very  good,  very  good.  Now*  would  you  mind  cutting 
it  down  and  giving  me  the  gist  of  it  in  a  page  or  two?" 
That  was  ten  years  ago.  The  other  day  the  same  young 
engineer  made  the  following  verbal  report  to  his  chief: 

Superintendent:  **Did  y'  inspect  that  machine?" 

Engineer:  *'Yes,  sir." 

Superintendent:  *'Any  good  for  our  purposes?" 

Engineer:  "Yes,  sir;  we  ought  to  have  one." 

Superintendent:  "All  right." 

Here  are  the  elements  of  a  complete  report.  And,  it 
might  be  added,  there  are  probably  more  reports  of  this 
latter  type  than  of  the  former. 

7.  Neatness.— La.ck  of  neatness  in  reports  usually  goes 
hand  in  hand  with  inaccuracy.  Indeed,  a  slovenly  report 
serves  to  draw  immediate  suspicion  upon  the  correctness 
of  the  data  and  the  soundness  of  the  conclusions,  for  it 
is  logical  to  infer  that  the  report  writer  who  is  careless  in 
the  form  of  his  report  will  also  be  careless  in  the  sub- 
stance. Since,  moreover,  a  slovenly  report  is  irritating 
and  more  difficult  to  read  than  a  neat  one,  it  follows  that 
the  reader  is  prevented  from  giving  his  complete  atten- 
tion to  the  content.  Carelessness  in  the  form  of  the  re- 
port may,  furthermore,  be  a  positive  bar  to  a  clear  under- 
standing of  the  ideas,  since  slovenliness  usually  means 
illegibility  of  letters  and  figures  and  inaccuracy  of  dia- 


3  54    COMPOSITION  OF  TECHNICAL  PAPERS 

grams.  Although  there  is,  perhaps,  the  possibiHty  of 
wasting  time  in  excessive  neatness,  the  habit  of  making 
reports  attractive  in  appearance,  while  not  as  important 
as  some  of  the  other  qualities  mentioned,  is  nevertheless 
much  to  be  desired. 

8.  Clearness. — -No  matter  how  good  the  data  may  be, 
how  sound  the  conclusions,  or  how  neat  the  appearance, 
a  report  will  be  useless  if  it  cannot  be  understood. 
^'Look  at  that  report,"  said  a  factory  superintendent 
recently  to  his  English  instructor  brother  who  was  visit- 
ing him;  "I  can't  make  head  or  tail  of  it,  and  yet  that 
man  is  a  college  graduate.  He  is  only  a  foreman  and 
will  never  be  anything  else  because  he  can't  make  himself 
understood."  On  examining  the  report  the  instructor 
found  it  full  of  errors  in  sentence  construction.  The 
factory  superintendent  did  not  know  the  names  for  these 
faults;  he  knew  merely  that  he  could  not  understand  the 
report,  and  that  was  enough.^  It  behooves  the  writer 
of  a  report,  therefore,  to  make  reasonably  certain  that 
the  sentences  of  which  the  report  is  made  up  are  under- 
standable; in  practice  this  means  the  avoidance  of  such 
errors  as  are  explained  and  illustrated  in  Chapter  V. 

9.  Logical  Errors. — Some  general  comments  on  the 
very  important  matter  of  logical  reasoning  have  already 
been  made  in  the  chapter  on  exposition  of  ideas  (see 
pages  260-261).  All  of  these  apply  in  report  writing. 
Without  meaning  in  the  least  to  be  inaccurate  or  dis- 
honest, inexperienced  writers  of  reports  are  prone  to  dis- 
tort facts  by  making  impossible  statements  and  sweeping 
generalizations.     All  statements  which  are  manifestly 

1  This  illustration  and  all  others  used  in  this  chapter  with  one  exception 
(that  on  p.  351)  were  not  invented  by  the  author  but  were  taken  from  his 
personal  experience  or  that  of  his  colleagues;  the  exception  is,  I  am  told,  a 
stock  story  frequently  used  by  engineers. 


REPORTS  355 

untrue  or  absurd  and  all  propositions  based  on  very  slight 
data  should  be  carefully  avoided.  The  post  hoc,  propter 
hoc  fallacy  is  of  frequent  occurrence  in  report  writing; 
this  is  the  bad  logic  which  leads  the  writer  to  assert  that 
a  phenomenon  results  from  another  phenomenon  merely 
because  it  chances  to  coincide  with  it,  whereas  in  fact  the 
relationship  between  the  two  may  be  merely  accidental. 
Another  frequent  logical  flaw  results  from  the  writer's 
failure  to  indicate  the  limits  of  error  in  his  conclusions, 
and  to  point  out  the  variations  possible  under  varying 
interpretations  of  the  submitted  data.  All  of  these  weak- 
nesses detract  from  the  force  and  value  of  a  report  even 
where  they  do  not  result  in  actual  misunderstanding, 
and  they  should,  therefore,  be  carefully  avoided. 

Organization  of  the  Report 

A  great  many  engineering  reports  consist  simply  of 
data  filled  forms,  and  such  reports  naturally  present  to 
the  writer  only  the  problem  of  collecting  the  data  and 
filling  in  the  blanks.  In  these  forms  the  arrangement  of 
details  is  carefully  planned,  usually  by  those  who  are  to 
read  the  reports,  on  the  basis  of  information  desired,  con- 
venience in  arrangement,  and  other  considerations. 
Many  times,  however,  the  organization  of  the  report  is 
left  with  the  writer,  and  his  problem  may  in  all  such 
cases  be  as  complex  as  though  he  were  writing  an  exposi- 
tion of  ideas.  It  need  hardly  be  said  that  a  clear  and 
logical  arrangement  of  the  parts  is  as  necessary  in  a  report 
as  in  any  other  technical  exposition.  In  the  matter  of 
plan  each  report  presents,  to  a  certain  extent,  its  own 
difficulties,  and  must,  therefore,  be  studied  independently. 
It  will  be  possible  here,  accordingly,  merely  to  record 


356    COMPOSITION  OF  TECHNICAL  PAPERS 

some  general  principles  of  organization  which  have  been 
found  useful.  Some  further  suggestions  for  the  organiza- 
tion of  student  reports  will  be  given  in  a  later  division  of 
the  chapter  (see  pages  358-365). 

One  of  the  simplest  forms  of  report  is  that  in  which 
the  arrangement  of  parts  is  chronological.  The  arrange- 
ment of  parts  of  an  inspection  report  may,  for  example, 
simply  correspond  with  the  order  in  which  the  various 
details  of  the  inspection  were  undertaken,  with,  of  course, 
proper  emphasis  upon  details  of  greatest  importance. 
In  such  a  report  the  writer  need  only  exercise  care  in 
marking  his  divisions  clearly. 

Where,  however,  the  divisions  of  the  report  must  be 
logically  and  not  merely  chronologically  arranged,  the 
problem  is  more  difficult.  In  such  cases  the  writer  must 
determine  the  order  of  topics  after  a  careful  consideration 
of  such  matters  as  interdependence  of  parts,  comparative 
understandability  of  details,  and  emphasis.  At  times  the 
relative  position  of  two  details  is  at  once  apparent;  it 
is  obvious,  for  exampje,  that  a  report  on  a  power  plant 
would  normally  consider  the  generating  elements  before 
taking  up  the  transmission  system.  At  other  times, 
however,  the  relative  position  of  parts  is  by  no  means  so 
easy  to  determine;  the  entire  question  may,  in  fact,  be 
exceedingly  complex,  as  is  indicated  by  the  specimen  re- 
port outlines  on  pages  379-387.  In  all  such  cases  it 
becomes  the  duty  of  the  writer  to  plan  his  report  accord- 
ing to  his  best  judgment  based  on  an  analysis  of  his  mate- 
rial and  of  the  particular  needs  of  his  reader. 

The  necessity  of  keeping  in  mind  the  point  of  view  of 
the  reader  is  coming  more  and  more  to  affect  the  form  of 
reports,  and  has  resulted,  especially  in  long  and  complex 
reports,  in  various  devices  for  saving  the  reader's  time. 


REPORTS  357 

For  example,  the  practice  is  increasing  of  putting  at  the 
beginning  of  the  report  a  brief  abstract  or  summary  of 
the  principal  items  taken  up  in  the  body.  To  this  is 
often  added  an  analytical  table  of  contents,  with  page 
references.  These  devices  serve  the  same  purpose  that 
head-lines  and  introductory  paragraphs  do  in  a  news- 
paper; they  enable  the  busy  reader  to  see  the  content  at 
a  glance.  Frequently,  too,  where  the  results  of  the  inves- 
tigation and  not  the  data  are  of  first  importance,  the  con- 
clusions are  put  at  the  beginning  of  the  report,  detached 
from  the  body,  so  that  the  reader  can  turn  to  them  at  once. 
Where  they  occupy  their  normal  position  at  the  end,  each 
conclusion  is  for  purposes  of  distinction  paragraphed 
separately.  When  the  report  is  designed  to  be  read  by 
lay  readers  it  is,  moreover,  frequent  practice  to  relegate  to 
an  appendix  all  highly  technical  discussions,  calculations, 
and  derivations  of  formulas.  Ease  in  reading  the  report 
is  frequently  increased  by  the  use  of  sub-titles  to  mark 
new  divisions,  and  by  various  other  visual  devices.  All 
of  these  tricks  assist  the  busy  reader  to  secure  at  once  a 
general  idea  of  the  scope  and  conclusions  of  the  report 
and  to  turn  immediately  to  any  division  which  may  espe- 
cially interest  him. 

Student  Reports 

The  difference  between  student  reports  and  profes- 
sional reports  has  already  been  indicated  (page  349). 
The  student  report  is  essentially  a  piece  of  drill  work. 
The  reader  of  the  report  cares  nothing  for  it  as  a  body  of 
collected  information  or  an  expression  of  expert  judgment; 
he  cares  everything  for  it  as  an  indication  of  the  student's 

ability.     The  student  report  writer  should  aim,  therefore, 
23 


358   COMPOSITION  OF  TECHNICAL  PAPERS 

to  convince  his  instructor  that  he  can  observe  intelli- 
gently, think  rationally,  and  record  accurately  and 
clearly.  Observing  intelligently  means  observing  with 
the  head  and  not  merely  with  the  eyes;  it  means  selecting 
unerringly  from  a  mass  of  details  those  which  are  signifi- 
cant and  worth  noting;  it  means  that  the  observer's 
brain  should  be  a  synthesizing  and  not  merely  a  record- 
ing organ,  and  should  be  constantly  at  work  relating  the 
details  observed  with  one  another  and  with  principles  and 
laws  which  they  illustrate.  Thinking  rationally  means 
using  intelligently  the  details  observed;  it  means  coordi- 
nating details,  inducing  conclusions,  testing  results,  and 
avoiding  logical  errors, — making  the  mind,  in  brief, 
master  of  the  information  gathered.  Recording  accu- 
rately and  clearly  means,  finally,  setting  down  data  and 
conclusions  with  care  that  the  written  record  be  an  exact 
report  of  the  work  of  the  brain  and  that  the  ideas  set 
forth  be  immediately  clear  to  the  reader.  These  general 
principles  of  report  writing  apply  to  all  types  of  student 
reports.  There  still  remain  a  few  special  considerations 
in  connection  with  the  laboratory  report,  the  inspection 
trip  report,  and  the  thesis. 

Laboratory  Reports. — A  student  laboratory  report  is  a 
record  of  a  test  or  experiment  conducted  by  a  student 
either  alone  or  in  cooperation  with  others.  Laboratory 
experiments  and  tests  aim  to  do  more  than  give  the 
student  manual  skill  in  handling  the  apparatus;  they  aim 
to  teach  him  principles  and  general  methods  and  to  in- 
crease his  capacity  for  thinking  rapidly  and  clearly. 
The  report  based  upon  them  should,  therefore,  be  more 
than  a  mere  mechanical  and  perfunctory  record  of  things 
seen  and  done;  it  should  reveal  an  understanding  of  the 
principles  involved. 


REPORTS  359 

The  form  of  the  laboratory  report  is  usually  prescribed 
by  the  instructor  or  by  the  laboratory  manual.  It 
varies,  of  course,  with  the  nature  of  the  experimental 
work  and  with  the  equipment  available.  The  following 
elements,  however,  usually  appear  in  the  order  named: 

1.  Introduction  J  which  includes  a  statement  of  the  ob- 
ject of  the  experiment  and,  frequently,  of  the  chemical, 
mechanical,  or  other  principles  involved. 

2.  Description  of  the  apparatus,  with  whatever  sketches 
are  necessary;  in  experiments  in  the  electrical  laboratory 
this  is  frequently  supplemented  by  a  diagram  of  connec- 
tions. 

3.  Method  of  conducting  the  experiment  or  test. 

4.  Conclusions  and  comments. 

5.  Where  necessary,  data  sheets j  curves,  and  other 
records  of  the  experiment. 

All  divisions  of  the  report  should  be  distinctly  labeled 
and  paragraphed  separately. 

Inspection  Trip  Reports. — An  inspection  trip  aims  to 
give  the  student  an  acquaintance  with  scientific  laws  and 
principles  in  application.  In  the  details  of  a  factory, 
railroad  station,  or  hydro-electric  plant  he  meets  the  em- 
bodiment of  the  scientific  knowledge  which  he  has  ac- 
quired in  lecture  hall  and  laboratory.  It  follows,  there- 
fore, that  the  most  important  element  in  an  inspection 
trip  is  intelligent  observation;  the  student  should  ob- 
serve details  not  as  meaningless  details  but  as  illustra- 
tions of  scientific  principles  in  operation;  and  he  should 
learn  to  select  for  his  inspection  trip  report  those  things 
which  are  significant.  A  mere  empty  catalogue  or  inven- 
tory of  things  seen  is  usually  a  pretty  clear  indication 
that  the  student  has  not  yet  learned  to  observe  with  the 
eye  of  an  engineer. 


36o    COMPOSITION  OF  TECHNICAL  PAPERS 

The  form  of  the  report  must  naturally  be  determined 
anew  for  each  trip.  One  of  the  best  methods  of  organiza- 
tion is  that  based  on  a  thoughtful  analysis  of  what  is 
significant  and  worth  reporting  and  an  arrangement  of 
these  details  by  topics.  A  mere  loose,  running  narrative 
is  likely  to  be  perfunctory  and  careless,  although  it  need 
not  be  if  the  writer  selects  the  details  of  his  report  care- 
fully and  remembers  that  he  is  writing  not  a  story  but  an 
exposition. 

The  following  directions  for  preparing  inspection  trip 
reports  may  be  taken  as  typical  of  those  frequently 
issued  to  engineering  students.  Due  emphasis  has  here 
been  put,  it  will  be  noted,  upon  an  intelligent  selection 
of  significant  details  in  gathering  the  data  and  upon  a 
correct  and  clear  use  of  English  in  preparing  the  written 
report.^ 

Civil   Engineering    Inspection    Trips — University 
OF  Wisconsin 

Instructions  for  Preparing  Trip  Reports 
April  I  1916 

Make-up. — I.  Reports  may  be  hand- written  in  ink  or  type- 
written. 

2.  Paper  shall  be  of  letter  size  (8^.^  in.  by  11  in.),  white,  and  of 
good  quality. 

3.  A  Manila  cover  shall  be  provided  to  which  the  pages  shall  be 
fastened  in  a  way  that  will  permit  of  easy  inspection. 

4.  A  letter  of  transmittal,  addressed  to  "The  Civil  Engineering 
Trip  Committee,"  shall  accompkny  the  report.  Such  comments 
or  suggestions  as  it  is  desired  to  make  shall  be  included  in  this  letter. 

5.  The  pages  shall  be  numbered  and  an  index  provided. 

*  These  directions  were  prepared  by  a  committee  of  civil  engineering 
instructors  and  are  here  reprinted  by  generous  permission  of  Professor  L. 
Van  Hagan  of  the  University  of  Wisconsin. 


REPORTS  361 

Length. — Instructions  as  to  the  minimum  number  of  words  that 
will  be  accepted  will  be  issued  for  each  trip.  There  is  no  maximum 
limit;  the  report  may  be  as  complete  as  desired. 

Method  of  Treatment. — The  report  shall  be  more  than  a  mere 
catalogue  of  places  visited  and  things  seen.  It  should  show  an 
understanding  of  the  broader  scientific  and  economic  features  of 
the  works  inspected. 

The  following  is  an  example  of  a  style  of  report  writing  that  is 
quite  common  and  wholly  unsatisfactory: 

"On  the  first  floor  are  found  the  ticket  offices,  an  information 
window,  a  lunch  room,  a  drug  store,  a  parcel  room  and  a  baggage- 
check  room.  On  the  second  floor  are  found  a  dining  room,  a  peri- 
odical booth,  and  toilet  rooms.  In  the  basement  are  found  an  air- 
washing  plant,  pumps,  and  a  lost-baggage  room." 

As  it  stands,  the  paragraph  is  of  no  particular  interest  to  the 
reader  and  indicates  no  more  valuable  quality  in  the  writer  than 
an  ability  to  see  and  record  the  obvious.  Any  person  who  can  read 
and  write  can  produce  a  report  of  that  character.  It  shows  no  great 
mental  development  nor  any  great  breadth  of  view.  But  if,  in- 
stead of  cataloguing  the  things  he  saw,  the  writer  had  given  a  dis- 
cussion of  why  the  ticket  ofiices  are  located  on  the  first  floor  in- 
stead of  on  the  second,  or  an  explanation  of  the  need  for  washed 
air  and  a  description  of  the  operation  of  the  air-washing  plant,  his 
report  would  have  considerable  interest  to  the  reader  and  would 
indicate  that  the  writer  had  grasped  something  of  the  purpose 
underlying  the  inspection. 

When  a  certain  piece  of  machinery  or  other  equipment  possesses 
individual  interest  because  of  its  unusual  size,  construction  opera- 
tion, or  field  of  service,  it  may  be  mentioned;  but  as  a  rule  there  is 
no  reason  to  list  the  engines,  machines,  boilers,  etc.,  that  are  usually 
more  or  less  the  same  in  all  plants. 

The  following  outlines  will  indicate  in  a  general  way  what  is 
meant  by  "  the  broader  scientific  and.economic  features  of  the  works 
inspected." 

I.  Manufacturing  Plants. 
I.  Purpose  of  the  Plant: 
The  product  of  the  plant. 
Industrial  importance  of  the  product. 


362    COMPOSITION  OF  TECHNICAL  PAPERS 

2.  Location  of  the  Plant: 

Efifect  upon  choice  of  location  of^ 
Cost  of  land, 
Transportation  facilities. 
Material  supply, 
Fuel  supply, 
Labor  supply. 

3.  General  Arrangement  of  the  Plant: 
Facilities  for  receiving  raw  materials. 

Movement  of  product  through  shops  during  manufacture. 
Shipping  facilities. 
Source  of  power. 

4.  Special  Features  that  Distinguish  the  Particular  Plant  from 

Others  of  its  Class: 
Interesting  details  of  manufacture,  etc. 

II.  Bridges,  Buildings^  Foundations,  and  Pavements, 

1.  Type: 
Type  used. 

Room  for  its  use  under  existing  conditions. 

2.  Methods  of  Erection  or  Installation: 
DiflSculties,  usual  and  unusual. 
Contractor's  equipment. 
Arrangement  of  contractor's  plant. 
Detail  methods. 

3.  Special  Features: 
Interesting  details. 
Condition  of  pavements. 
Methods  of  operation  of  bridges. 
Maintenance. 

Spelling. — The  spelling  shall  be  correct. 

English. — The  language  shall  be  as  concise,  clear,  and  grammati- 
cal as  the  ability  of  the  writer  will  permit.  It  shall  be  chosen  with 
care  and  precision;  loose,  sweeping,  inaccurate  statements  shall  be 
avoided.  The  writer  shall  aim  to  avoid,  on  the  one  hand,  ama- 
teurish expressions,  and,  on  the  other,  stilted  phrasing.  A  report 
consisting  of  incomplete  and  disconnected  sentences  carelessly 
thrown  together  will  not  be  accepted. 

It  is  not  to  be  expected  that  a  student  will  be  able  to  produce  an 
acceptable  piece  of  work  without  devoting  some  thought  and  care 


REPORTS  363 

to  its  preparation.  The  system  of  sitting  down  and,  without 
previous  thought,  writing  until  a  certain  number  of  words  have  been 
put  together,  and  submitting  the  product  without  further  correction 
usually  results  in  an  unacceptable  report.  It  is  recommended  that 
an  outline  be  prepared  before  the  actual  writing  is  commenced. 
This  outline  should  include  the  various  items  that  are  to  be  covered 
in  the  report.  The  preparation  of  such  an  outline  will  necessitate 
a  consideration  by  the  student  of  the  relative  values  of  the  various 
items,  will  enable  him  to  select  the  more  important,  and  will  aid 
him  to  obtain  a  better  proportioned  report. 

The  following  miscellaneous  suggestions  point  out  some  of  the 
more  common  weaknesses  of  reports  that  have  been  submitted 
in  previous  years: 

1.  Avoid  ending  a  sentence  weakly. 

Examples:  "Cranes  weighing  one  hundred  and  fifty  tons  are 
now  being  built." 
"An  inspection  of  the  plant  was  made." 

Comment:  Put  the  "punch"  at  the  end  of  the  sentence,  where 
it  is  most  effective.  The  sentences  should  read:  "Cranes 
are  now  being  built  that  weigh  as  much  as  one  hundred  and 
fifty  tons."     "An  inspection  was  made  of  this  plant." 

2.  Avoid  loose,  sweeping,  and  inaccurate  statements. 
Examples:  "As  we  passed  through  the  shops,  we  saw  engines 

of  every  type  from  the  smallest  switch  engine  to  the  largest 
mallet  type,  including  all  types  that  have  been  developed  of 
late  years,  Atlantic,  Pacific,  and  Mikado  included." 
Comment:  No  such  wonderful  collection  of  locomotives  was 
actually  seen. 

3.  Avoid  statements  that  are  ohviodsly  incorrect. 

Examples :  Speaking  of  a  placer  dredge, — "  It  Is  very  massive 
in  construction,  weighing  more  than  a  million  tons." 
In  the  boiler  shops  there  was  "an  accumulator  for  15001b. 
pressure"  for  supplying  air  to  the  riveting  machine. 

Comment:  Both  statements  are  so  far  from  actual  facts  that 
the  inaccuracy  should  be  apparent  to  any  third  year  student 
in  Civil  Engineering. 

4.  Avoid  the  split  infinitive. 

Example:  "If  he  works  on  one  plan  for  a  time,  then  changes 
to  another,  only  to  again  and  again  change  .    .    .    ." 


364    COMPOSITION  OF  TECHNICAL  PAPERS 

Comment:  The    infinitive    is    "to    change."     The    sentence 

should  read,"  ....  only  to  change  again  and  again." 
5.  Avoid  loose  use  of  *Uhey"  and  "their.^' 

Example:  "New  engines,  cars,  and  their  parts  are  built  and 

assembled  in  the  shops.     They  cast  their  own  wheels  and 

forge  all  their  own  driving  wheels." 
Comment:  No  antecedent  is  given  for  "  they."     It  is  used  in  a 

loose,  conversational  way  that  has  no  place  in  careful  writing. 

Theses. — Engineering  theses  are  virtually  long  reports 
based  upon  experiments,  tests,  and  other  investigations. 
Their  aim  is  to  give  the  student  training  in  creating  or 
assisting  to  establish  a  proposition  by  evidence  more 
extensive  and  complex  than  that  involved  in  the  simpler 
laboratory  tests  and  experiments.  Engineering  theses 
are  not  different  in  nature  from  the  reports  of  investiga- 
tions conducted  by  experts  in  government  and  private 
laboratories,  and  for  this  reason  some  of  the  best  models 
for  theses  may  be  found  in  the  various  government  bulle- 
tins and  technical  papers,  which  are  readily  accessible. 

Where  the  field  of  investigation  is  not  artificially  re- 
stricted, the  first  step  to  be  taken  in  thesis  writing  is  usu- 
ally a  careful  analysis  of  the  problem  and  limitation  of  the 
field  of  investigation.  This  is  necessary  that  the  writer 
may  not  undertake  a  problem  which  cannot  be  handled 
adequately  with  the  equipment  at  his  disposal. 

The  next  step  in  a  great  many  theses  is  the  determina- 
tion of  the  extent  and  results  of  investigations  already 
completed  in  the  same  field.  This  will  ordinarily  mean  a 
diligent  search  for  written  records  of  these  investigations; 
they  may  be  found  in  books  but  are  more  likely  to  be 
found  in  that  immense  and  never  finished  encyclopaedia 
of  scientific  information,  the  technical  journals.  Theses 
of  former  students,  since  they  are  not  likely  to  be  the 
work  of  finished    experts,    should    be  used   with   cau- 


REPORTS  365 

tion.  Indeed,  all  second-hand  information,  as  has 
already  been  said  in  the  preceding  chapter,  should  be 
employed  with  due  regard  for  its  reliability.  In  the 
finished  report  due  credit  should  be  given,  usually  in  a 
foot-note,  for  all  second-hand  material,  and  if  the  ob- 
ligations have  been  at  all  extensive,  it  is  well  also  to 
include  in  an  appendix  a  bibliography  of  books  and  arti- 
cles referred  to. 

Subsequent  stages  in  the  collection  of  data  and  the 
composition  of  the  thesis  will  be  determined  by  the  nature 
of  the  investigation  and  cannot,  therefore,  even  be  sug- 
gested here.  An  examination  of  the  organization  of 
material  in  government  reports  of  investigations  may 
prove  helpful  but  should  not  be  allowed  to  result  in  an 
attempt  at  exact  reproduction  of  form,  which  is  certain 
to  end  unsatisfactorily. 

A  final  word  about  thesis  writing:  excepting  where  the 
thesis  subject  is  automatically  narrow  and  specialized, 
— such,  for  example,  as  comparative  tests  of  two  gas 
engines, — the  thesis  is  likely  to  be  perfunctory  unless  it 
reflects  a  genuine  and  vital  interest  on  the  part  of  the 
writer.  He  should  be  willing  to  live  with  his  subject 
and  scrutinize  everything  with  regard  to  its  possible  con- 
nection with  his  thesis.  If,  for  example,  he  is  a  civil 
engineering  student  investigating  the  comparative  values 
of  two  kinds  of  pavement,  a  chance  item  on  the  subject 
in  his  technical  journal,  a  chance  remark  of  a  friend  or  of  a 
road-mender,  a  suspicious  bulge  or  crack  in  a  pavement 
which  he  happens  to  be  observing  should  alike  be  re- 
garded as  possible  material.  And  it  is  only  by  being 
thus  perpetually  alive  to  his  investigation  that  he  can 
create  a  report  which  will  be  solid  and  vital. 


366    COMPOSITION  OF  TECHNICAL  PAPERS 

STUDENT  REPORTS^ 

[Because  of  the  variety  of  forms  no  attempt  has  been 
made  here  to  reproduce  a  representative  selection  of 
student  reports.  The  following  are  not  designed  to 
serve  as  models  hut  merely  to  provide  material  for  class 
analysis;  they  should  be  supplemented  by  student  reports 
brought  to  class  from  the  laboratories.  In  editing,  the 
data  sheets  and  graphs  of  the  original  reports  have  been 
omitted]. 

I.  Cross-bending  Test  of  a  Wooden  Beam 

Object. — The  object  of  this  test  is  to  study  the  action  of  and  the 
internal  stresses  in  a  wooden  beam  subjected  to  cross-bending 
loads. 

Apparatus. — 


The  apparatus  for  this  test  consisted  of  a  Johnson  testing  ma- 
chine, scale,  knife-edges,  deflectometer,  clamp,  and  Oregon  fir 
beam.  The  beam  was  placed  on  knife-edges  below  the  Johnson 
testing  machine  so  that  the  load  would  be  applied  half  way 
between  the  supports.  One  of  these  supports  or  knife-edges 
rested  on  a  scale  which  measured  half  the  applied  load.  In  the 
middle  of  the  beam  directly  under  the  load  was  attached  a  dial 
wound  deflectometer.  The  sketch  above  explains  the  principle 
on  which  this  instrument  works.  Two  strips  of  wood,  S,  one  on 
each  side  of  the  beam,  were  supported  on  pins  placed  on  the  neutral 

1  For  the  hydraulic  laboratory  reports  the  editor  is  indebted  to  Professor 
C.  I.  Corp  of  the  College  of  Engineering.  University  of  Wisconsin. 


REPORTS 


367 


axis  of  the  beam  directly  over  the  end  supports.  On  these  strips 
pulley  P  and  the  dial  and  drum  D  were  attached.  The  dial  was 
graduated  to  thousandth  parts  of  an  inch.  Clamps,  C,  were 
fastened  with  screws  to  the  side  of  the  beam  under  the  load,  and 
pulleys,  W,  were  fastened  to  the  lower  part  of  these  clamps.  From 
the  point  A  on  strips  S  a  number  36  copper  wire  passed  over  the 
pulleys,  W,  and  P,  to  the  druni  on  the  recording  dial.  The  arrange- 
ment of  the  deflectometer  apparatus  was  such  that  the  strips,  5, 
remained  stationary  as  the  beam  was  deflected.  It  is  obvious  that 
a  double  value  of  deflections  will  be  recorded  on  the  dial  since  the 
vertical  wires  leaving  pulleys  W  measure  the  deflections  on  each 
side  of  the  beam. 

Method. — The  load  was  applied  gradually  at  B  (see  sketch)  in 
increments  of  about  400  lbs.  The  first  crack  in  the  beam  occurred 
under  a  load  of  4100  lbs.,  and  failure  resulted  from  a  load  of  4500 
lbs,,  although  a  load  of  5450  lbs.  was  applied  before  the  beam  was 
totally  ruptured. 

Conclusions. — The  facts  to  be  noted  of  this  test  are  that  the 
moduli  of  rupture  and  of  elasticity  of  Oregon  fir  are  about  }4,  and  1^4 
respectively  of  those  of  mild  steel,  and  that  the  energy  of  rupture 
per  cubic  inch  is  very  much  less  than  the  energy  of  rupture  in 
tension.  This  latter  fact  can  be  attributed  to  the  decrease  of 
stresses  from  the  outer  fibers  to  the  neutral  axis  of  the  beam  and 
from  the  load  to  the  supports  in  a  beam  under  cross-bending  loads, 
whereas  a  specimen  under  tension  or  compression  loads  has  every 
particle  subjected  to  equal  stresses. 

2.  Fluid  Differential  Gages 
Object. — The  object  of  this  experiment  is  to  study  the  principle 
of  the  differential  gage  and  to  determine  the  gage  coefficient. 
Apparatus. — 


f  o 

o  6 -A.  i 

K-    -A-   -A 


Fig.  I. 


Fig.   2. 


368    COMPOSITION  OF  TECHNICAL  PAPERS 

The  above  are  diagrammatic  sketches  illustrating  the  appa- 
ratus used  in  this  experiment.  Fig.  i  shows  that  used  with 
fluids  heavier  than  water,  and  Fig.  2  that  used  with  fluids  lighter 
than  water.  The  two  fluids  were  respectively  bromof orm  and  kero- 
sene. The  difference  in  heads  is  obtained  by  varying  the  water 
levels  in  the  tubes  and  thus  producing  different  pressures.  Vernier 
scales  are  provided  on  all  tubes  so  that  the  scales  may  be  read  more 
accurately. 

As  water  is  poured  into  M,  the  pressure  at  A  increases,  forcing  the 
kerosene  up  at  A  and  down  at  B.  As  the  height  of  the  water 
column  is  increased  in  N,  the  kerosene  is  forced  in  the  opposite 
direction. 

Let  N  =  the  specific  gravity  of  water,  and  S  =  the  specific 
gravity  of  the  fluid. 

Then  since  the  pressures  at  the  same  levels  A  and  Ai  in  the  closed 
tube  are  the  same  for  equilibrium,  we  may  equate  these  pressures, 
obtaining : 

NLi  +  DN  -  DN  =  NL2  +  DN  -  DS 
N{Li  -  Li)  =  D{N  -  S). 

But  N{Li  —  La)  is  the  difference  in  pressure  or  head;  .*.  let  h  = 
NiLi  -  U). 

Then  h  =  D{N  -S)ox^={N-S) 

iV  -  5  is  a  constant.     Let  iV  -  5  =  C. 
Then  ~  =  C, 

the  gage  coefficient 

In  the  case  of  the  fluid  bromoform,  heavier  than  water,  we  obtain 
by  equating  the  pressure  equations  at  the  level  Ai,  A: 

NLx  +  hD  =  NL2  4-  DS 
N{U-U)  =  D(S  -  N), 

Denoting  N(Li  —  La)  by  h,  as  explained  above, 

/;  =  D{S  -  N) 


REPORTS  369 

where  S  is  greater  than  N  since  in  this  case  the  bromoform  is 
heavier  than  water; 

the  gage  coefficient. 

As  shown  on  the  following  data  sheet,  the  deflection  in  the  levels 

of  the  kerosene,  the  lighter  fluid,  was  much  greater  than  that  in  the 

case  of  the  bromoform,  which  made  D  much  larger  in  the  former 

h 
case.     Hence,  since  the  coefficient  C  —  ^'  this  would  be  greater 

in  the  case  of  the  heavier  fluid  as  shown  in  the  data. 

The  reason  why  it  is  not  desirable  to  take  the  readings  of  differ- 
ence of  head  less  than  0.2  ft.  is  that  a  very  small  error  in  reading 
would  cause  a  relatively  large  error  in  the  gage  coefficient.  More- 
over, when  the  liquid  rises  or  falls  only  a  small  amount,  there  is  a 
greater  tendency  for  the  fluid  to  cling  to  the  sides  because  of 
capillary  attraction,  which  produces  an  error  in  the  result. 

Besides  capillary  attraction  and  its  effects  other  causes  for  error 
which  might  take  place  are  irregularity  in  the  inner  surface  of  the 
tube,  or  the  presence  of  dirt  and  dust.  Moreover,  the  scale  read- 
ings were  not  placed  on  the  glass  according  to  calibrations  but 
were  on  a  separate  background,  and  if  the  diameter  of  the  tube 
were  smaller  than  it  should  be  so  that  the  fluid  would  rise  higher 
in  the  tube  than  it  should  normally,  the  circumstance  of  the  scale's 
not  being  calibrated  on  the  glass  by  test  would  result  in  no  detec- 
tion of  the  error  but  the  recording  of  a  higher  reading. 

It  is  not  desirable  to  compute  gage  coefficients  from  the  density 
of  the  fluids  because  the  density  varies  with  the  temperature,  and 
because  the  density  of  the  same  fluid  varies  Moreover,  we  are 
determining  the  gage  coefficient  with  a  definite  apparatus,  and  the 
gage  coefficient  is  changed  because  of  the  errors  mentioned  above, — 
variation  of  the  size  of  the  tube,  clinging  of  the  fluid  to  the  tube, 
etc. — all  of  which  would  affect  the  coefficient  of  this  gage  but  would 
not  have  been  taken  into  consideration  had  we  used  method  of 
density. 

[Two  data  sheets  have  been  omitted  in  editing.] 

3.  The  Orifice 
Object. — To  study  the  effect  of  change  in  head  on  the  coeflScient  of 
discharge  and  to  determine  the  coefficient  of  discharge  for  an  orifice. 


3  7o   COMPOSITION  OF  TECHNICAL  PAPERS 

Apparatus. — 


A  sketch  of  the  apparatus  used  in  this  experiment  is  shown 
above.  The  water  enters  the  receiver  at  A  under  pressure,  and 
flows  out  of  the  orifice  B  into  one  of  two  openings  in  the  conveyor 
C.  One  of  the  openings,  the  upper,  conveys  the  water  to  the 
measuring  tank  D,  which  sits  on  a  Fairbanks-Morse  scales.  The 
other  entrance  to  the  conveyor  leads  to  a  passage  which  carries  the 
water  to  the  sewer.  A  lever  is  provided  by  which  the  conveyor 
can  be  quickly  raised  or  lowered,  thus  transferring  the  flow  from 
the  sewer  to  the  tank  or  vice  versa. 

The  pressure  in  the  receiver  can  be  regulated  by  the  valve  at  i4, 
thus  giving  any  desired  head  on  the  orifice.  The  pressure  head  is 
measured  by  the  piezometer  E  for  low  heads  and  by  the  mercury 
gage  F  for  high  heads. 

Method. — ^The  zero  gage  reading  was  determined  by  making  the 
water  level  with  the  bottom  of  the  orifice.  The  reading  of  the 
gage  plus  half  the  diameter  of  the  orifice  gave  the  zero  reading. 

Runs  were  then  taken  with  different  heads  on  the  orifice,  the 
heads  being  adjusted  by  means  of  the  inlet  valve.  Readings  of  the 
gage  were  taken  every  minute.  The  discharge  was  measured  by 
means  of  the  scales. 

Formula, — The   quantity   of    discharge   in   cu.   ft.    per   sec.  = 

cfV^ 


REPORTS 


371 


Considering  velocity  of  approach,  the  formula  becomes  q  = 

CF^2g  (AH -J  ,  where  Vi  is  the  velocity  of  approach. 

Sample  computations;  Run  No.  i : 
Rate  of  discharge  in  cu.  ft.  per  sec.  = 


62.5  X  40s 


•0197s 


Mean  velocity  of  approach 


.01975 


.07  ft.  per  sec. 


.62  X  .7854 
Fi2  /.o7\  2 

Actual  head  = 1-  h  =  I — j    +  1.057  =  1.057. 

Theoretical  discharge  =  I- — j    X  •7^54'\/2g  X  1.057  =  .0317  cu. 
ft.  per  sec. 


Coefficient  of  discharge  =  - — ^  =  .624. 


Coefficient  of  contraction 


.0^17 


Conclusions. — The  value  of  the  coefficient  is  higher  than  those 
values  given  in  the  book.  The  results  of  Run  No.  2  do  not  seem 
to  be  consistent  with  the  results  of  the  other  runs,  indicating  the 
probability  of  error. 

[Three  data  sheets  have  been  omitted  in  editing.] 

4.  The  Orifice 

Object. — The  object  of  this  experiment  is  to  determine  the  coeffi- 
cient of  discharge  from  a  standard  orifice. 
Apparatus. — 


U  s^*f€*  UJ.._ 


372    COMPOSITION  OF  TECHNICAL  PAPERS 

The  general  outlay  of  the  apparatus  used  in  this  experiment 
is  as  shown  in  the  above  figure.  Water  is  allowed  to  enter 
through  valve  (i)  from  the  supply  main.  The  water  flows  into 
the  storage  pipe,  through  the  tank,  and  over  the  orifice  into  the 
cylindrical  tank,  which  is  placed  on  scales  so  that  the  water  dis- 
charged may  be  weighed.  The  elevation  head  of  the  water  is 
obtained  by  the  water  gage  reading,  but  in  case  this  head  exceeds 
the  maximum  gage  reading,  valve  (3)  is  closed  and  valve  (2)  is 
opened,  so  as  to  allow  the  water  to  drain  out.  Then  valve  (4)  is 
opened,  which  connects  with  the  mercury  gage  used  in  the  deter- 
mination of  the  larger  heads.  With  the  data  as  shown  on  the  ac- 
companying data  sheets,  the  coefficient  of  discharge  may  be  deter- 
mined by  the  formula: 

q  =  cFy/T^ 

where  q  is  the  rate  of  discharge, 

c  is  the  coefficient  of  discharge, 
J^  is  the  area  of  orifice, 
and      h  is  the  head. 

Method. — The  first  thing  done  in  this  experiment  was  to  remove 
the  orifice  from  the  drum  and  measure  its  diameter;  this  we  found 
to  be  .84  in.  After  replacing  the  orifice,  we  closed  the  mercury 
valve  and  opened  the  main  supply  valve,  filling  the  tank  or  drum 
until  the  water  flowed  from  the  orifice.  Then  by  means  of  a  small 
cock  under  the  drum  the  water  level  was  lowered  until  it  was  just 
level  with  the  lower  edge  of  the  orifice.  The  gage  was  then  read, 
and  by  adding  one-half  the  diameter  of  the  orifice,  the  height  of  the 
center  of  the  orifice  was  thus  computed.  Then  the  air  cock  on  top 
of  the  drum  was  opened,  and  water  allowed  to  enter  the  drum 
through  the  supply  main  until  water  came  out  of  the  air  cock,  thus 
showing  that  all  air  was  removed  from  the  drum.  Then  the  main 
supply  valve  was  opened  so  as  to  allow  more  water  to  enter  until 
the  desired  head  was  obtained  for  the  first  run.  The  run  was  then 
taken,  observations  of  the  head  on  the  water  gage  being  made  every 
minute  and  the  water  being  allowed  to  discharge  into  the  tank  on 
the  scales,  where  it  was  weighed  after  each  run.  Owing  to  a  break 
in  the  mercury  tube  the  mercury  gage  could  not  be  read  so  as  to 
get  a  check  on  the  readings  for  determining  the  heads.  During 
each  run  the  diameter  of  the  jet  just  outside  the  orifice  was  calipered. 
It  is  difficult  to  determine  this  dimension  exactly,  but,  as  shown  on 


REPORTS  373 

the  data  sheet,  the  diameter   remained    practically  constant  for 
varying  heads. 

The  diameter  of  the  drum  (inside)  was  8  inches.     The  style  of 
the  orifice  was  circular. 

Sample  computations: 

Initial  gage  reading,  bottom  of  orifice  =  3.705' 
}'^  diameter  of  orifice  =    .035' 

Elevation  of  centre  of  orifice  =  3.740' 

Actual  rate  of  discharge, 

^"^ =  .0196  cu.  ft.  per  sec. 


62.4  X  5  X  60 
Theoretical  rate  of  discharge, 
q  =  Fy/2gh    F  =  -  X  .0049 

=  -  X  .0049  X  8.03\/i.o4  =  .0316  cu.  ft.  per  sec. 

4 

Coefficient  of  discharge, 

.0196 
c  =  — ^  =  .62 
.0316 

q 

Mean  velocity  of  approach  =  -. ^* 

•^    ^^  drum  area 

.0196 


© 


.0561  ft.  per  sec. 


72 
Velocity  head  =  — 

(.o<;6i)2 
h  =  ^  /  ^    =  .0000488  ft. 
64.4 

area  of  jet 


Coefficient  of  contraction 


area  of  orifice 
TT        /^\  2 
4>^\i2/  (.68)2 


-T^^.^Y^    ^Mr    '^^^ 


-m^  '■' 


Practically  constant. 
(Three  data  sheets  have  been  omitted  in  editing.) 
24 


374. 


COMPOSITION  OF  TECHNICAL  PAPERS 


5.  Boiler  Inspection  Report 

Madison,  Wisconsin, 
May  15,  1916. 
To  the  Board  of  Regents, 
University  of  Wisconsin, 
Madison,  Wisconsin. 
Gentlemen : 

In  compliance  with  your  written  order  of  April  5,  19 16,  I  have 
inspected  the  Number  9  350  horsepower  Babcock  and  Wilcox  boiler 
unit  fitted  with  a  Roney  Mechanical  Stoker,  which  is  located  at 
the  new  heating  station.  A  careful  inspection  was  made  in  order 
to  ascertain  its  present  condition  and  to  determine  whether  or  not 
immediate  repairs  are  necessary.  The  examination  did  not  include 
any  eflficiency  tests,  but  consisted  simply  of  an  examination. 

The  drum  was  thoroughly  examined  from  the  inside.  Above 
the  water  line  the  surface  of  the  drum  was  slightly  pitted  as  was  the 
dry  pipe.  This  pitting  was  less  than  would  be  expected  and  was 
not  enough  to  impair  the  strength  of  the  drum  or  dry  pipe.  There 
was  considerable  scale  deposit  below  the  water  line,  indicating  that 
the  quality  of  feed  water  used  might  be  improved.  This  scale  was 
J^  2  of  an  inch  thick  in  some  places.  The  condition  of  the  riveting 
throughout  the  drum  was  good.  The  water  pipes  leading  from  the 
drum  were  in  good  condition  and  very  clean. 

The  vertical  headers  were  then  inspected.  Their  outward  ap- 
pearance was  not  very  good;  it  was  evident  that  several  hand  holes 
were  leaking  and  allowing  the  steam  to  escape  and  to  deposit  scale 
on  the  outside  of  the  headers.  Several  hand  holes  were  removed, 
and  their  gasket  packing  was  inspected.  The  gaskets  used  con- 
sisted of  forms  of  tin  in  which  was  contained  asbestos.  The  use 
of  this  particular  type  of  gasket  accounts  for  the  leaks.  The  pipes 
as  seen  from  the  open  hand  holes  were  clean  and  in  good  condition, 
an  indication  that  the  scale  deposit  is  being  removed  at  regular 
intervals. 

The  mechanical  stoker  was  in  good  operating  condition  as  were 
the  coal  chute  and  ash  removers.  In  fact,  from  outward  appear- 
ances the  complete  fire  box  seemed  to  be  in  good  condition.  How- 
ever, an  inside  inspection  of  the  fire  box  brought  out  the  fact  that 
the  grates  were  in  poor  condition.  The  replaceable  units  of  the 
grates  were  all  worn  out,  which  will,  of  course,  seriously  impair  the 


REPORTS  375 

satisfactory  operation  of  the  stoker.     The  fire  brick  lining  in  the 
fire  box  was  in  good  condition. 

In  conclusion  I  would  say  that  the  Boiler  is  in  fairly  good  oper- 
ating condition.     The  following  changes  are  recommended: 

1.  That  the  scale  deposit  in  the  drum  be  removed  and  that  steps 
be  taken  to  improve  the  quality  of  the  feed  water  used. 

2.  That  the  hand  holes  in  the  header  be  removed,  and  that  soft 
lead  gaskets  be  substituted  for  the  tin  and  asbestos  ones  now  in 
use  in  the  header  holes. 

3.  That  the  grate  be  repaired  by  putting  in  a  complete  set  of 
replaceable  units. 

The  above  repairs,  which  could  be  made  at  a  small  cost,  would 
place  the  Boiler  in  first  class  condition. 

Respectfully  submitted 
(Sig.)  R.  J.  Bell 


6.  Brief  Report  on  Geology  Trip  to  the  Dells  of  the 
Wisconsin 

Object  of  the  Trip. — The  object  of  the  trip  was  to  ascertain  the 
composition,  structure,  and  causes  therefore,  of  the  rock  composing 
the  gorge  known  as  the  "Dells  of  the  Wisconsin." 

General  Layout  and  Description. — The  portion  of  the  Wisconsin 
River  known  as  the  Dells  is  that  part  of  its  course  where  the  water, 
which  has  a  width  of  several  thousand  feet  upstream,  is  suddenly 
forced  to  go  through  a  gorge  which  varies  from  75  to  200  feet  in 
width.  The  total  length  of  the  Dells  is  about  four  miles.  The 
walls  on  either  side  are  between  50  and  75  feet  high.  The  depth 
of  the  water  was  not  ascertained  but  must  be  considerable  through- 
out the  gorge.     The  topography  is  essentially  young  in  character. 

Composition  and  Structure  of  the  Rock. — The  rock  is  composed 
almost  entirely  of  sandstone.  Bedding  is  practically  horizontal, 
indicating  no  extensive  earth  movements  since  its  formation.  The 
layers  of  stone  are  quite  thin  and  joints  are  very  prominent,  giving 
rise  to  numerous  canyons,  which  in  some  cases  have  smaller  tribu- 
tary canyons. 

Special  Features. — Cross-bedding  of  the  sandstone  is  quite 
prominent. 

The  canyons  are  in  most  cases  practically  at  right  angles  to  the 


376    COMPOSITION  OF  TECHNICAL  PAPERS 

river,  a  condition  which  is  due  to  the  fact  that  they  were  formed  by- 
joints. 

Pot-holes,  formed  by  the  cutting  action  of  the  sand  in  whirlpools, 
are  found  in  some  of  the  canyons. 

At  the  place  marked  A  on  the  map  is  a  former  channel  of  the 
river,  now  dry  except  at  periods  of  high  water. 

Cause  of  Topography. — The  cause  for  this  gorge  was  the  blocking 
of  the  Wisconsin  River  by  glaciers  at  a  point  somewhat  north  of  the 


Dells,  which  forced  it  to  change  its  course.  The  new  course  led 
across  this  outcrop  of  comparatively  soft  sandstone,  and  the  water 
wore  its  way  down  through  the  stone.  The  canyons  leading  away 
from  the  main  gorge  were  started  by  joints  in  the  rock,  through 
which  water  from  the  surrounding  country  flowed  into  the  river, 
and  in  so  doing,  further  increased  the  depth  and  width  of  the  fissures. 


REPORTS  377 

PROFESSIONAL  REPORTS 

[The  variety  of  forms  of  professional  reports  as  well  as 
the  length  of  many  of  them  has  precluded  the  publica- 
tion here  of  a  representative  selection.  The  following 
will  serve  as  examples  of  certain  types.  They  should  be 
supplemented  in  class  discussions  by  municipal,  public 
service,  and  other  easily  secured  reports.] 

I.  Letter  Reporting  a  Test 

[The  following  is  a  very  common  type  of  report, — 
the  letter  to  a  superintendent  from  his  subordinate 
reporting  a  test  and  making  recommendations  based 
upon  it.  A  great  many  professional  reports  take  the 
form  of  letters; long  ones  addressed  to  boards  of  directors, 
committees,  or  similar  bodies  usually  have  a  "Letter  of 
Transmittal"  prefixed  to  them.  The  letter  is  addressed 
to  Building  because  it  was  sent  from  one  office  to  another 
within  the  same  building.] 

[Letterhead  with  place  of  writing] 

March  2,  191 7. 
Mr.  J.  L.  Adams,  E.  E.  D., 
Building. 
Dear  Sir: 

This  morning  voltage  readings  were  taken  at  the  Johnson  Com- 
pany in  Johnsonville  as  follows : 

Voltage  dropped  from  222  to  178  on  starting,  with  the  motor  on 
one  phase  of  the  power  circuit.  On  a  second  trial  with  the  same 
connections  and  taking  15  seconds  longer  to  start,  the  voltage 
dropped  from  222  to  198.  The  lower  reading  was  obtained  at  the 
instant  that  the  short-circuiting  clutch  went  in. 

On  the  opposite  phase  with  the  same  conditions  as  above  the 
voltage  range  was  from  222  to  202. 

Readings  were  then  taken  when  the  motor  was  started  with  the 
voltmeter  on  the  lighting  circuit.     Here  the  voltage  dropped  from 


378    COMPOSITION  OF  TECHNICAL  PAPERS 

no  to  loo  when  the  clutch  went  in  20  seconds  after  the  motor  was 
started.  When  30  seconds  was  used  to  start  the  motor,  the  voltage 
range  was  from  no  to  103. 

Readings  were  also  taken  at  meter  number  9830  on  a  secondary- 
system  fed  from  transformers  on  the  Albany  Road.  Here  the  volt- 
age dropped  from  109  to  102  during  the  starting  of  the  motor. 

It  seems  evident  from  the  above  tests  that  the  Johnson  Company 
have  been  responsible  for  the  lights  dipping  at  Edmonds'  Hotel, 
and  on  other  installations  on  the  Johnsonville  circuits.  In  the  case 
of  the  Edmonds'  Hotel  this  would  be  more  noticeable  because  the 
installation  is  on  the  same  primary  tap  as  the  motor. 

Attached  is  a  requisition  for  doing  away  with  this  condition  by 
running  primary  to  the  Albany  Road. 

Respectfully  submitted, 
(Sig.)  J.  R.  Mears. 

2.  Abstract  of  Report  of  Committee  on 
Street  Lighting 

[The  following  is  the  abstract  preceding  a  seventeen 
page  committee  report  read  recently  at  a  convention  of 
the  National  Electric  Light  Association.  It  should  be 
noted  that  it  provides  at  a  glance  an  idea  of  the  scope 
and  content  of  the  report  and  that  it  was  therefore  very 
useful  to  members  who  had  not  the  time  to  read  the 
entire  article.] 

Abstract 

The  primary  purpose  of  street  lighting  is  to  promote  facility  and 
safety  of  movement  during  the  hours  when  sunlight  is  not  available, 
and  the  report  is  therefore  confined  to  the  technical  problems  en- 
countered in  meeting  these  requirements. 

In  Section  I  the  relation  of  street  illumination  to  artificial  lighting 
in  general  is  pointed  out  and  the  historical  development  of  street 
lighting  as  a  police  aid  is  discussed. 

In  Section  II  the  science  of  illuminating  streets  is  treated  under 
the  following  heads:  Intensity,  Distribution  and  Direction  of  Light; 
Glare;  Lamp  Sizes;  Locations  and  Fixtures. 

Section  III  consists  of  a  technical  description  of  various  systems 
of  distribution. 


REPORTS  379 

In  conclusion,  the  Committee  reports  that  in  addition  to  the  fore- 
going technical  matters,  it  has  considered  the  questions  of  standard 
forms  of  specifications  and  contracts  together  with  that  of  costs, 
but  that  these  matters  can  not  be  made  a  part  of  the  report  at  this 
time. 

3.  (Table  of  Contents  of)  Comparative 
Tests  of 
Run  of-Mine  and  Briquetted  Coal  on  the 
Torpedo  Boat  Biddle^ 
By  Walter  T.  Ray  and  Henry  Kreisinger 
[The  following  table  of  contents  is  reprinted  to    show 
the  plan  of  a  government  report  based  on  a  series  of  com- 
parative tests.     Other  outlines  of  similar  reports  are 
reprinted  on  pages  41-42.] 

Page 

Introduction 5 

General  statement 5 

Tests  at  Norfolk 5 

Personnel 6 

Coals  and  briquets 7 

Objects  of  the  tests 7 

Appliances 7 

Boat  and  boiler  plant 7 

Flue-gas  sampler 10 

Spark  catchers 11 

The  blower 13 

Methods  of  conducting  tests 13 

General  statement 13 

Starting  and  closing 13 

Weight  of  ash  and  refuse 13 

Weight  of  coal  fired 14 

Weight  of  water  fed  to  boiler 14 

Feed- water  temperature 15 

Flue-gas  sampling 15 

Flue-gas  temperature 15 

^   Furnace  temperature iS 

Gas  pressures  (" drafts  ") iS 

»  Bureau  of  Mines,  Bulletin  33  (iQn)-  Reprinted  by  permission  of  the 
Director  of  the  Bureau. 


380   COMPOSITION  OF  TECHNICAL  PAPERS 

Page 

Steam  pressures 15 

Moisture  in  steam '.....  15 

Smoke 15 

Weight  of  sparks 16 

Chemical  analyses 16 

Observed  data  and  calculated  items 16 

Effect  of  rate  of  combustion 16 

The  tabular  showing 16 

Notes  on  individual  tests 21 

Data  and  calculations  shown  graphically 23 

Explanation  of  figures 23 

On  capacity  developed 23 

On  evaporation 23 

On  dry  flue  gases 25 

On  smoke 26 

On  distribution  of  heat 28 

On  heat  losses 28 

On  heat  absorption 28 

On  unaccounted-for  losses 31 

On  run-of-mine  coal  and  briquets 32 

On  flue-gas  and  furnace  temperatures 32 

On  true  boiler  efiiciency 35 

On  pressure  drop 36 

On  sparks 38 

On  weight  of  air 38 

On  speed  of  fan 40 

Deductions 40 

Economy 40 

QJombustion  space 42 

Relative  capacity  of  storage  space 43 

Transferring  fuel  from  bunkers  to  fireroom 43 

Conclusions 43 

A  fundamental  principle  in  the  combustion  of  smoky  fuels.  ...  44 

Publications  on  fuel  testing 49 

ILLUSTRATIONS 

[Omitted  in  reprinting] 

TABLES 

[Omitted  in  reprinting] 


REPORTS  381 

4.  The  Rate  of  Burning  of  Fuse,  as  Influenced 
BY  Temperature  and  Pressure^ 

By  Walter  O.  Snelling  and  Willard  C.  Cope 

[The  following  is  the  Introduction  of  a  twenty-five 
page  report  of  an  investigation  conducted  for  the  Bureau 
of  Mines.  The  Table  of  Contents  of  the  report  will  be 
found  on  page  41.  It  will  be  noted  that  the  Introduction 
is  a  general  clearing  ground  for  the  rest  of  the  report, 
which  consists  of  an  account  of  the  various  tests  made 
and  a  statement  of  the  conclusions  drawn  from  them]. 

INTRODUCTION 

Miners*  fuse,  known  also  as  "safety  fuse,"  "running  fuse"  and 
"Bickford  fuse,"  consists  essentially  of  a  core  of  gunpowder  sur- 
rounded by  protective  wrappings  or  coatings.  It  is  used  in  blasting 
as  a  gunpowder  "train"  for  transmitting  ignition  to  the  charge  of 
explosive,  and  its  purpose  is  to  provide  a  time  interval  between 
the  lighting  of  a  "shot"  and  the  explosion  of  the  charge. 

Such  fuse  best  fulfills  its  purpose  when  its  rate  of  burning*  is  uni- 
form, so  that  the  interval  between  the  moment  of  lighting  the 
"shot"  and  the  moment  at  which  the  "shot"  explodes  is  definite 
for  any  given  kind  and  length  of  fuse.  In  mining  operations  it  is 
assumed  that  the  fuse  used  burns  at  a  regular  and  uniform  rate, 
and,  believing  this,  the  miner  in  his  daily  work  cuts  off  such  lengths 
of  fuse  as  should  give  the  particular  time  intervals  desired. 

There  are,  however,  conditions  that  cause  variations  in  the  rate 
of  burning  of  fuse,  some  causing  a  marked  retardation  and  others 
causing  a  decided  acceleration.     Hence  it  has  seemed  necessary  to 

*  Technical  Paper  6  (19 12)  of  the  Bureau  of  Mines.  Reprinted  by  permis- 
sion of  the  Director  of  the  Bureau. 

•  In  this  paper,  the  rate  at  which  fuse  burns  is  expressed  in  units  of  time 
as  "30  seconds  per  foot,"  and  not  in  units  of  length,  as  "2  feet  per  minute," 
though  the  latter  form  is  more  in  accord  with  ordinary  usage  in  describing 
speed  or  motion.  The  reason  for  using  the  form  "seconds  per  foot"  or 
"seconds  per  meter"  is  that  the  time  in  which  a  given  length  of  fuse  burns  is 
the  information  the  miner  desires.     [Authors'  note.] 


382     COMPOSITION  OF  TECHNICAL  PAPERS 

investigate  the  conditions  that  bring  about  these  variations,  since 
any  marked  change  in  the  rate  of  burning  of  fuse  can  cause  an 
accident. 

For  instance,  where  a  number  of  shots  are  to  be  fired  in  one  round, 
it  is  not  always  possible  to  determine  by  the  usual  method  of  count- 
ing that  every  shot  has  fired.  Hence,  should  one  piece  of  fuse  have 
been  subjected  to  such  conditions  as  produce  a  retardation  in  its 
rate  of  burning,  the  miner  may  go  back  to  the  shot  before  all  the 
holes  have  fired  and  encounter  an  explosion  as  he  nears  the  face. 
On  the  other  hand,  should  conditions  be  such  as  to  cause  an  increase 
in  the  rate  of  burning  of  one  piece  of  fuse  out  of  a  number  used  in 
a  single  round  of  holes,  it  may  be  possible  for  this  piece  of  fuse  to 
bring  about  an  explosion  before  the  miner  has  been  able  to  light  all 
of  the  other  pieces  and  reach  a  point  of  safety. 

It  will  thus  be  seen  that  either  retardation  or  acceleration  in  the 
rate  of  burning  of  fuse  can  readily  become  the  cause  of  accident, 
and  accordingly  the  study  of  the  conditions  under  which  the  rate  of 
burning  of  fuse  is  so  changed  as  to  cause  the  fuse  to  burn  more  rap- 
idly or  more  slowly  becomes  of  particular  importance. 

Miners  have  frequently  noticed  that  fuse,  when  surrounded  by 
very  dense  stemming  material,  as  in  a  hole  that  has  been  firmly 
tamped,  burns  faster  than  it  should.  In  this  case  the  dense  and 
impermeable  stemming  prevents  the  free  escape  of  the  gases  from 
the  powder,  and  so  compresses  them  in  their  attempt  to  escape  as 
to  bring  about  a  decided  quickening  in  the  rate  of  burning.  As  the 
use  of  firm  stemming  is  nearly  always  desirable,  one  can  readily  see 
that  information  as  to  the  degree  of  quickening  in  the  rate  of  burning 
of  fuse  under  these  conditions  is  essential  in  order  that  the  miner 
may  in  such  cases  know  what  additional  length  of  fuse  is  necessary 
to  provide  for  the  increased  rate  of  burning. 

Retardation  in  the  rate  of  burning  of  fuse  is  a  serious  fault.  Cases 
are  known,  though  fortunately  very  few,  in  which  a  piece  of  fuse 
has  seemingly  stopped  burning,  and  yet  after  an  interval  of  one  or 
more  hours  has  brought  about  the  explosion  of  the  charge  to  which 
it  was  attached.  Cases  of  this  sort  never  happen  with  fuse  that  is 
in  good  condition,  but  may  sometimes  happen  when  fuse  is  of  poor 
manufacture  or  has  been  subjected  to  unfavorable  conditions  of 
moisture  or  temperature. 

The  conditions  that  are  believed  to  be  most  active  in  bringing 
about  either  a  retardation  or  an  acceleration  in  the  rate  of  burning 


REPORTS  383 

of  time  fuse  have  been  investigated  experimentally,  and  the  results 
that  have  been  obtained  will  be  classified  in  this  report  under  effects 
due  to:  (a)  Pressure;  (6)  temperature;  (c)  moisture;  (d)  mechanical 
injury. 

Nature  and  Composition  of  Fuse 

Many  varieties  of  fuse  have  been  manufactured.  They  differ 
mainly  in  the  nature  of  the  protecting  layers  or  coatings,  or  the 
manner  in  which  the  waterproofing  is  effected.  In  general,  all 
types  of  fuse  are  similar  in  structure,  and  in  all  of  them  the  essential 
element  is  a  core  of  fine-grained  gunpowder  wrapped  about  by 
threads  of  hemp,  jute,  or  cotton. 

The  fuse  is  made  by  a  machine  in  which  a  number  of  jute  threads, 
usually  10,  are  spun  around  the  outlet  tube  of  a  hopper  or  funnel, 
through  which  the  fine-grained  gunpowder  is  descending.  The  out- 
let tube  is  so  arranged  in  relation  to  the  revolving  cords  (called  the 
"spinning  threads")  that  the  stream  of  gunpowder  delivered  from 
the  hopper  is  caught  within  a  channel  of  cord.  A  second  set  of 
threads  (called  "countering"),  usually  of  cotton,  is  spun  in  the 
opposite  direction  around  the  first  set  that  contains  the  powder 
core,  and  by  means  of  these  two  sets  of  threads  spun  in  opposite 
directions  the  core  of  fine  powder  is  held  in  place,  the  twisted  cords 
forming,  in  effect,  a  tube  within  which  the  powder  is  contained. 
Sufl&cient  tension  is  kept  upon  the  cords,  during  the  operation  of 
spinning,  to  insure  their  holding  the  core  of  gunpowder  closely. 
No  space  not  filled  with  gunpowder  should  be  present. 

Descriptive  Terms 

There  are  several  varieties  of  fuse  made  after  the  general  method 
just  described.  In  examining  most  of  these  types  of  fuse  a  fine 
thread,  called  the  "center  thread,"  will  usually  be  found  in  the 
powder  core.  This  thread  passes  through  the  hopper  containing 
the  powder,  and  its  function  is  to  cause  the  powder  to  pass  in  a 
constant  stream  through  the  small  aperture  at  the  bottom,  and  to 
prevent  the  clogging  of  the  fine  opening  that  delivers  the  stream  of 
powder  to  the  fuse  that  is  being  formed. 

In  referring  to  the  various  types  of  fuse,  use  will  be  made  of  the 
term  "raw  fuse"  or  "wrapped  core"  to  describe  the  core  of  gun- 


384    COMPOSITION  OF  TECHNICAL  PAPERS 

powder  surrounded  by  the  spinning  threads  and  first  countering,  as 
just  described. 

Fuse  is  divided  into  three  main  classes  according  to  the  nature  of 
the  work  for  which  it  is  intended.  Fuse  of  class  i  is  suitable  for 
dry  work,  such  as  stump  blasting  and  quarrying.  Fuse  of  class  2  is 
intended  for  damp  or  wet  work,  as  in  coal  mining,  or  in  surface 
work  where  mud,  rain,  or  dampness  is  encountered.  Fuse  of  class 
3  is  suitable  for  very  wet  work,  such  as  may  be  necessary  in  tunnel- 
ing, shaft  driving,  etc. 

Cotton,  hemp,  and  single-countered  fuse  are  of  the  first  type,  and 
consist  of  "raw  fuse"  that  has  been  drawn  through  a  bath  of  water- 
proofing material  and  finished  with  whiting,  talc,  or  some  similar 
substance  to  prevent  the  separate  loops  of  a  coil  from  sticking 
together.  In  cotton  fuse  the  spinning  threads  as  well  as  the  coun- 
tering are  of  cotton  instead  of  jute.  Single-tape  fuse  and  double- 
countered  fuse  are  of  the  second  type,  and  consist  of  raw  fuse  that 
has  been  twice  coated  with  waterproofing  material,  double  coun- 
tered or  taped  and  finished  like  fuse  of  type  i.  Double  tape,  triple 
tape,  gutta  percha,  and  taped  double-countered  fuse  belong  to  the 
third  type.  These  consist  of  raw  fuse  that  has  been  coated  with 
waterproofing  material  and  taped  or  double  countered,  and  then 
finished  with  a  coating  of  black  varnish  and  whiting  or  talc,  etc.,  or 
with  a  heavy  coating  of  white  china  clay  mixed  with  glue  to  form 
a  paste. 

Composition  of  Fuse  Powder 

The  gunpowder  which  forms  the  core  of  safety  fuse  is  usually  in 
very  fine  grains.  At  times  the  waste  from  sporting  powder  is  used 
in  the  preparation  of  fuse,  but  usually  a  special  powder  is  made  for 
this  purpose.  An  analysis  of  a  sample  of  fuse  powder  gave  the 
following  results: 

Analysis  of  fuse  powder 

Moisture 00 .  63 

Nitrate  of  potash 74-42 

Sulphur 1 1 .  96 

Charcoal 12 .  99 


REPORTS  385 

The  size  of  the  grains  of  this  powder  as  determined  by  a  sieve 
test  was  as  follows : 

Size  of  grains  of  fuse  powder 

Caught  on  40-mesh  sieve 7.7 

Caught  on  60-mesh  sieve 40  •  53 

Caught  on  80-mesh  sieve 13  •  95 

Caught  on  loo-mesh  sieve 27 .  50 

Through  loo-mesh  sieve 10.31 


100.00 

5..  Report  on  the  Proposed  Hydro-electric  Devel- 
opments ON  the  Peshtigo  River  at 
High  and  Johnson's  Falls^ 

Daniel  W.  Mead 

Consulting  Engineer 

Madison,  Wis.  Chicago,  111. 

[The  following  is  the  first  part  of  a  typical  report  ad- 
dressed by  a  consulting  engineer  to  the  company  which 
has  engaged  his  services.  The  name  and  address  of  the 
president  of  the  company  and  the  name  of  the  company 
in  the  Letter  of  Transmittal  have  been  changed;  other- 
wise the  report  has  not  been  altered.  The  number  of 
pages  reprinted  in  proportion  to  the  total  number  may 
be  seen  from  the  Table  of  Contents.] 

TABLE  OF  CONTENTS 

Page 

Letter  of  Transmittal 7 

Location  of  Proposed  Installation 9 

Field  Work 9 

Canal  Project 10 

Establishment  of  Gaging  Stations 10 

Topographical  Survey 10 

The  Peshtigo  River 10 

The  Power  of  a  River 12 

Power  of  the  Peshtigo  River 13 

»  Reprinted  by  permission  of  Professor  Mead. 


386    COMPOSITION  OF  TECHNICAL  PAPERS 

Page 

Gagings  of  the  Peshtigo  River 14 

Flow  of  a  Stream  under  Ice  Conditions 15 

Comparative  Drainage  Areas  on  the  Peshtigo  River 15 

Comparative  Flow 16 

Relative  Power  at  Johnson's  Falls 17 

The  Power  Hydrograph 17 

Power  from  Minimum  Flow , -  17 

Effect  of  Pondage  and  Storage 18 

Storage  at  High  Falls 20 

Effects  of  Evaporation  on  Pondage 20 

Effects  of  Ice  on  Pondage 21 

Effects  of  Storage  on  Power  at  High  Falls 21 

Development  at  High  Falls  with  a  75'  Head 22 

Storage  with  a  75'  Head 22 

Development  at  High  Falls  with  an  85'  Head 23 

Comparison  of  75'  and  85'  Heads 23 

Maximum  Power  Development 24 

Auxiliary  Power  Available 24 

Rainfall  on  the  Peshtigo  River  Drainage  Area 25 

Estimates  of  Flow  based  on  other  Rivers 25 

Power  of  the  Peshtigo  River  at  High  Falls  and  based  on  the 

Flow  of  the  Wisconsin  River  at  Merrill 26 

Power  of  the  Peshtigo  River  at  High  Falls  based  on  the  Flow 

of  the  Menominee  River  at  Iron  Mountain 27 

Conclusions  as  to  Economical  Power  Development 28 

The  Selection  of  Machinery  for  the  High  Falls  Plant 28 

Influence  of  Load  Distribution  on  Equipment 29 

Recommendations  for  the  Immediate  Installation 30 

Installation  of  Turbines 30 

Machinery  Purchased 32 

Power  Station 33 

Dams 34 

Transmission  Line 35 

Market 35 


APPENDIX  A 
Laws  of  Wisconsin  Relative  to  Overflow  Land 36 


REPORTS  387 

APPENDIX  B 
Law  of  Wisconsin  Relative  to  Proposed  Development 38 

APPENDIX  C 
Notes  on  Water  Power 40 

APPENDIX  D 
Relations  of  Stream  Flow  to  Rainfall 44 

APPENDIX  E 
Methods  of  Calculating  the  Relation  of  Power  and  Pondage. .     48 

[A  list  of  illustrations  and  diagrams  has  been  omitted  in  reprint- 
ing.] 

Letter  of  Transmittal 

Madison,  Wisconsin,  December  9,  1908. 
Mr.  R.  G.  Owens,  President, 

Midland  Hydro-Electric  Power  Company, 
York,  Wisconsin. 

Dear  Sir:  I  have  been  requested  by  the  Board  of  Directors  of 
the  Midland  Hydro-Electric  Power  Company  to  report  on  the  pro- 
posed hydro-electric  developments  on  the  Peshtigo  River  at  High 
and  Johnson  Falls,  and  the  transmission  to  Green  Bay,  Wisconsin, 
of  the  power  so  generated. 

In  making  this  report  I  have  endeavored,  as  far  as  practicable, 
to  simplify  all  technical  descriptions  and  details  and  to  explain  all 
deductions  in  such  a  manner  that  any  business  man  may  be  able 
to  fully  understand  the  facts  in  the  case,  to  follow  the  argument,  to 
understand  the  basis  of  the  conclusions  and,  hence,  to  form  his 
own  opinion  as  to  the  validity  of  the  same. 

While  every  engineering  problem  must  require  for  its  correct 
solution  the  application  of  technical  knowledge  and  experience,  yet 
a  correct  solution  must  be  based  fundamentally  on  sound  reasoning 
and  business  principles.  It  has  long  been  my  opinion  that  if  such 
a  problem,  together  with  the  data  on  which  its  solution  must  be 
based,  is  clearly  set  forth,  the  validity  of  the  conclusions  regarding 
the  same  will  become  apparent  and  will  appeal  to  the  judgment  of 


388    COMPOSITION  OF  TECHNICAL  PAPERS 

any  thinking  business  man.  While  technical  training  is  required 
to  thoroughly  understand  the  details  of  such  a  problem,  yet  the 
general  proposition  itself,  if  worthy  of  consideration,  must  appeal 
to  sound  common  sense  and  business  judgment;  and  if  the  entire 
proposition  is  carefully  set  forth,  it  is  seldom  necessary  to  rely 
wholly  on  the  judgment  of  the  expert  in  such  matters. 

I  trust  in  the  following  pages  I  have  been  able  to  so  completely 
cover  this  subject  as  to  make  the  reasons  for  and  validity  of  my 
recommendations  fully  apparent  after  a  careful  reading  of  this 
report.  Very  respectfully, 

Daniel  W.  Mead, 
Consulting  Engineer. 

Location 

The  proposed  hydro-electric  installations  considered  in  this  re- 
port are  to  be  constructed  at  High  Falls  and  Johnson's  Falls  on 
the  Peshtigo  River  in  Marinette  County,  Wisconsin,  about  four- 
teen (14)  miles  northwest  of  the  Village  of  Crivitz  or  the  Chicago, 
Milwaukee  and  St.  Paul  Railway  Station,  known  as  Ellis  Junction. 
The  sites  of  these  developments  are  in  the  northeastern  part  of 
the  State  of  Wisconsin  just  north  of  a  line  due  west  from  Marinette, 
and  about  sixty  (60)  miles  northwesterly  from  the  City  of  Green 
Bay.     (See  Diagrams  I  and  III.) 

Field  Work 

Preliminary  Examination  and  Report. — I  first  made  an  examina- 
tion of  this  locality  in  the  early  spring  of  1906,  and  caused  a  pre- 
liminary topographical  survey  to  be  made  of  the  river  from  a  point 
about  one  (i)  mile  below  Johnson's  Falls  to  Caldron  Falls,  about 
thirteen  (13)  miles  farther  up  the  river.  At  that  time  no  gagings 
had  been  made  of  this  stream  but,  based  on  the  preliminary  survey 
together  with  the  flow  records  of  adjacent  rivers,  a  report  was 
made  under  date  of  April  17,  1906,  which  included  an  estimate 
of  the  amount  of  power  that  might  be  developed  and  the  approxi- 
mate cost  of  such  development. 

Canal  Project. — Following  this  report,  a  preliminary  survey  was 
made  for  a  possible  canal  route  from  a  point  above  High  Falls  to 
the  foot  of  Johnson's  Falls,  to  determine  the  feasibility  of  develop- 


REPORTS  389 

ing  these  two  falls  in  a  single  installation.  Such  a  plan  was  found 
to  be  feasible,  and  a  preliminary  report  to  this  effect  was  duly  made. 
The  laws  of  Wisconsin,  while  providing  for  the  condemnation  of 
land  for  flowage  purposes  (see  Appendix  A),  make  no  provision 
which  will  permit  of  the  diversion  of  a  stream  from  its  natural  bed 
without  the  consent  of  the  riparian  owners  between  the  points  of 
diversion  and  return  of  the  waters.  As  such  consent  could  not,  in 
this  case,  be  obtained,  the  canal  proi'ect  above  outlined  has  not 
been  further  considered. 

Establishment  of  Gaging  Station, — In  the  latter  part  of  August, 
1906,  a  gaging  station  was  established  on  the  Peshtigo  River  near 
Herman's  farm,  about  six  (6)  miles  above  the  Village  of  Crivitz. 
Daily  readings  of  the  gage  have  been  made  from  that  date  to  the 
present  time. 

Topographical  Survey. — In  the  fall  of  1906  a  detailed  topograph- 
ical survey  of  the  Peshtigo  River  was  made  from  a  point  about  one 
mile  below  Johnson's  Falls  to  a  point  above  Twin  Falls,  and  to  a 
contour  height  of  11 20  feet  above  sea  level  in  order  to  obtain  a  basis 
for  the  preparation  of  plans  for  the  power  development.  This  sur- 
vey has  since  been  supplemented  by  a  further  survey  extending 
the  information  to  a  higher  elevation  (elevation  1130)  in  order  to 
determine  the  feasibility  of  raising  the  dam  and  impounding  a 
greater  amount  of  water  for  storage  purposes.  On  the  basis  of 
these  examinations  and  surveys,  numerous  maps  and  plans  have 
been  prepared  and  are  now  on  file  at  this  oflfice. 


The  Peshtigo  River 

The  drainage  area  of  the  Peshtigo  River  lies  in  the  northeastern 
part  of  Wisconsin,  within  the  glaciated  area  which  contains  the 
numerous  small  lakes  for  which  Wisconsin  is  famous.  Its  location 
relative  to  the  other  drainage  areas  of  the  State  is  shown  on  Dia- 
gram No.  I,  and  its  area  above  the  points  considered  in  this  report 
is  shown  on  a  larger  scale  on  Diagram  No.  II.  The  location  of  the 
drainage  area  relative  to  the  Menominee  and  Wisconsin  Rivers, 
with  which  its  flow  is  compared  in  this  report,  is  shown  on  Diagram 
No.  III. 

In  Bulletin  No.  XX  of  the  Wisconsin  Geological  and  Natural 
History  Survey,  entitled  "Water  Powers  of  Wisconsin,"  Professor 


390    COMPOSITION  OF  TECHNICAL  PAPERS 

L.  S.  Smith  thus  describes  the  Peshtigo  River:  "The  drainage  area 
of  the  Peshtigo  River  includes  1123  square  miles  with  an  extreme 
length  of  80  miles  and  an  average  width  of  only  14  miles.  The 
upper  two-thirds  of  its  length  is  in  the  pre-Cambrian  regions,  while 
in  the  lower  third  it  crosses  successively  the  Potsdam  sandstone 
and  the  lower  magnesian  and  Trenton  limestones.  The  most  im- 
portant falls  and  rapids  are  all  in  the  pre-Cambrian  regions.  Be- 
cause of  the  narrow  watershed,  the  Peshtigo  tributaries  are  of  small 
extent. 

"The  Peshtigo  River  rises  in  the  highest  land  of  Northern  Wis- 
consin. At  Crandon  the  river  has  an  elevation  of  1620  feet  above 
the  sea.  In  a  length  of  about  94  miles  it  descends  1040  feet,  empty- 
ing into  Lake  Michigan  (Green  Bay)  about  seven  miles  south  of 
Marinette.  This  average  gradient  of  n  feet  per  mile  gives  rise  to 
more  and  larger  rapids  than  any  other  river  in  Wisconsin.  This 
fact  together  with  the  usual  high  and  rocky  banks  insures  numerous 
water  powers.  The  relatively  small  drainage  area  is  more  than  off- 
set by  the  size  of  the  rapids." 

The  portion  of  the  river  to  which  the  power  development  herein 
considered  is  more  directly  related,  lies  between  the  foot  of  John- 
son's Falls  and  the  foot  of  Caldron  Falls  about  thirteen  miles  above. 
The  fall  between  these  two  points  is  130  feet,  most  of  which  it  is 
intended  to  utilize  in  the  proposed  power  developments. 

A  profile  of  the  river  between  the  points  named  is  shown  on  Dia- 
gram IV,  and  a  map  of  the  river,  on  a  larger  scale  between  the  points 
mentioned,  is  shown  on  Diagram  V. 

The  legislative  act  under  which  it  is  proposed  to  carry  out  the 
improvement  was  approved  April  26,  1899,  and  published  April 
29,  1899,  and  is  given  in  full  in  Appendix  B. 

The  Power  of  a  River. — The  power  of  a  river  depends  upon  two 
factors,  viz.,  the  head  or  fall  that  can  be  developed  and  maintained 
at  the  point  of  development,  and  the  flow  or  quantity  of  water 
that  is  available  for  power  purposes  at  the  same  point.  These 
factors  will  vary  considerably  at  different  times  during  each  year. 

Head. — The  head  will  commonly  decrease  during  high  water,  due 
to  the  backing  up  of  the  tailwater  or  water  below  the  dam.  Under 
low  water  conditions,  when  storage  immediately  above  the  dam  is 
used,  the  head  will  frequently  decrease  as  the  pond  or  reservoir  is 
drawn  upon  for  an  extra  supply  of  water  during  seasons  in  which 
tb?  natural  flow  of  the  stream  is  not  suflScient  for  power  purposes. 


REPORTS 


391 


Flow. — The  flow  of  a  stream  will  vary  from  the  extremely  high 
maximum  flows  during  floods  when  a  superabundance  of  water  is 
available,  to  the  extreme  low  flows  which  obtain  both  in  the  dry 
season  of  summer,  during  which  most  of  the  rainfall  is  utilized  in 
plant  growth,  and  during  the  extreme  cold  seasons  of  winter  when 
the  springs  are  frozen  and  the  flow  is  frequently  greatly  reduced 
on  this  account. 

A  water  power  development  to  be  commercially  satisfactory  must 
usually  be  such  as  will  furnish  constant  and  continuous  power  under 
all  the  conditions  by  which  its  use  is  modified.  The  broadest 
possible  knowledge  of  the  stream  flow  is  therefore  essential  in  order 
to  determine  with  accuracy  the  continuous  power  that  can  be  de- 
veloped and  sold  to  economical  advantage. 

The  most  desirable  information  concerning  the  flow  of  a  stream 
in  relation  to  the  development  of  its  power  is  the  accurate  measure- 
ments of  the  flow  of  the  stream  itself  at  the  point  at  which  it  is  to 
be  developed.  For  a  complete  knowledge  of  the  subject  it  is  neces- 
sary that  these  gagings  be  continued  not  only  throughout  the 
varying  conditions  of  a  single  year,  but  that  they  shall  also  be  con- 
tinued through  a  series  of  years  during  which  all  of  the  modifying 
conditions  which  influence  and  control  the  flow  shall  have  reached 
the  extremes  to  which  they  are  subjected.  It  is  very  rare  that 
such  complete  data  are  available  and  in  almost  every  case  where 
water  power  is  to  be  developed,  it  becomes  essential  to  utilize  in- 
formation more  or  less  limited  in  extent  and  by  the  careful  consider- 
ation of  other  data  to  so  supplement  and  extend  the  observations 
that  correct  conclusions  can  be  drawn  for  all  conditions  which  are 
likely  to  obtain. 

All  factors  in  the  problem  must  be  carefully  examined  and  con- 
sidered if  a  complete  knowledge  of  the  power  of  a  stream  and  the 
variations  to  which  it  may  be  subject  are  to  be  fully  known  and 
appreciated. 


CHAPTER  X 

BUSINESS  LETTERS 

Introduction 

A  t3rpe  of  composition  which  the  young  engineering 
college  graduate  is  certain  to  be  called  upon  to  write  is 
the  business  letter.  Indeed,  business  letters  and  reports 
are  more  than  likely  to  form  the  bulk  of  his  writing  for  the 
first  few  years  and  perhaps  even  for  the  whole  of  his  pro- 
fessional career.  With  the  great  increase  in  the  amount 
of  business  done  by  correspondence  has  come  in  recent 
years  more  attention  to  the  art  of  business  letter  writing. 
Business  houses  and  all  companies  doing  business  by 
correspondence  have  found  that  poor,  slovenly  letters 
do  not  pay,  and  that  careless  letters  lead  too  often  to 
irritation,  misunderstanding,  loss  of  trade,  and  even 
litigation.  Accordingly,  the  best  companies  have  system- 
atized carefully  the  work  of  writing  their  letters  and 
have  tried  to  create  and  follow  a  high  standard.  It 
therefore  behooves  the  young  employee  of  an  engineering 
firm  to  know  something  of  the  best  practice  in  business 
letter  writing  and  to  keep  his  official  correspondence  up 
to  as  high  a  standard  as  possible. 

In  this  brief  chapter  no  attempt  will  be  made  to  give 
more  than  a  few  comments  on  the  general  qualities  of 
good  business  letters,  the  accepted  forms,  and  the  make- 
up of  a  few  of  the  types  which  engineers  are  most  likely 
to  write.    Engineering  students  who  expect  to  engage  in 

392 


BUSINESS  LETTERS  393 

the  commercial  work  of  their  profession,  and  who  there- 
fore desire  to  study  commercial  correspondence  further, 
are  referred  to  the  many  excellent  books  on  the  subject. 
Many  of  the  practices  of  modern  business  correspond- 
ence have  resulted  from  the  necessities  of  standardiz- 
ing letter  forms  and  thereby  economizing  time  and 
energy.  For  it  should  be  remembered  that  a  business 
letter,  unlike  a  social  letter,  must  be  regarded  from  two 
points  of  view;  not  only  is  it  the  vehicle  of  communication 
between  correspondents,  but  it  also  provides,  either  in  its 
original  form  or  in  carbon  copy,  a  permanent  record  of 
the  business  transaction  involved.  In  modern  practice 
all  business  letters  received  and  carbon  copies  of  all 
letters  sent  out  are  classified,  usually  by  subject,  and 
carefully  filed.  As  these  files  are  constantly  referred  to 
for  data,  it  is  apparent  that  for  ease  of  filing  and  conven- 
ience of  reference  uniform  practices  must  be  followed. 
For  this  reason  a  standard  size  of  paper  is  employed, 
letters  are  written  on  only  one  side  of  the  sheet,  the  date, 
inside  address,  subject  of  the  letter,  and  other  details  are 
always  included,  and  certain  other  standard  practices 
are  regularly  followed.  Uniformity  in  these  particulars 
results  in  maximum  convenience  and  economy  for  both 
correspondents.  The  following  qualities  of  good  busi- 
ness letters  and  the  details  of  their  form  are  not,  therefore, 
accidental,  but  result  almost  without  exception  from  the 
general  demands  of  usefulness  and  economy. 

Qualities  of  the  Good  Business  Letter 

I.  Good  Appearance. — A  business  letter  is  the  repre- 
sentative of  the  firm  which  sends  it.  It  is  as  important, 
therefore,  that  it  present  a  neat,  trim  appearance  as  that 


394    COMPOSITION  OF  TECHNICAL  PAPERS 

an  employee  representing  the  firm  be  well  groomed. 
The  slovenly  letter,  like  the  slovenly  salesman,  is  not 
pleasant  to  meet  and  does  not  merit  any  particular 
attention. 

Good  appearance  means,  ordinarily,  that  the  letter 
must  be  typewritten;  the  days  of  the  old,  half  legible 
scrawl  have  passed.  In  the  matter  of  spacing  tastes 
differ;  the  usual  practice,  however,  excepting  in  very 
short  letters,  is  to  single  space  the  lines  within  the 
paragraph  and  to  double-space  between  paragraphs. 

The  neat  letter  will,  furthermore,  be  well  balanced  on 
the  page;  that  is,  it  will  not  be  crowded  into  a  part  of  the 
page,  but  will  be  written  with  uniform  margins  on  all 
sides. 

In  the  matter  of  letter-heads  good  taste  dictates  sim- 
plicity. The  printing  at  the  top  of  the  letter  should  be 
well  arranged  and  neat  in  appearance.  It  is  not  good 
form  to  crowd  the  top  and  left-hand  margin  with  adver- 
tising matter,  which  is  almost  certain  to  give  the  page 
a  messy  appearance  and  to  detract  attention  from  the 
subject  matter  of  the  letter. 

The  paper  should  be  white,  of  good  weight,  and  of  the 
regulation  letter  size  (83^^  by  ii  inches).  The  practice 
of  writing  short  letters  on  half-sheets  is  disappearing 
because  of  the  inconvenience  of  filing  and  handling  sheets 
of  varying  sizes. 

In  general,  the  letter  should  reflect  in  appearance  the 
good  taste  and  care  of  the  writer  and  of  the  firm  which 
he  represents.  The  question  of  good  form  is,  finally, 
too  important  a  matter  to  be  left  entirely  with  the 
stenographer. 

2.  Brevity. — The  necessity  for  economizing  the  valu- 
able time  of  both  writer  and  reader  dictates  that   the 


BUSINESS  LETTERS  395 

business  letter  be  as  brief  as  is  practicable.  Brevity  does 
not  mean  crude  curtness;  it  means  simply  stating  the 
subject  of  the  letter  promptly  and  continuing  without 
rambling.  Ordinarily  a  letter  should  be  confined  to  a 
single  page,  although  there  are,  of  course,  times  when  it 
must  be  longer.  Letters  which  contain  a  very  slight 
idea  enshrouded  in  a  mist  of  words  cause  amusement 
where  they  do  not  create  irritation. 

3.  Completeness. — A  letter  should  never  be  so  brief 
that  it  is  incomplete  in  content.  The  writer  should  in- 
variably be  careful  to  include  all  information  which  his 
correspondent  will  need.  Failure  to  do  this  will  result 
in  the  necessity  of  further  correspondence  and  in  conse- 
quent delay,  inconvenience,  and  economic  loss. 

4.  Carefulness. — In  addition  to  being  complete,  the 
information  contained  in  a  letter  should  be  accurate. 
Quotations,  specifications,  details  of  an  order  should  all 
be  carefully  checked  over,  for  mistakes  are  costly. 
Furthermore,  the  writer  of  a  business  letter  should  be 
careful  never  to  commit  to  writing  any  statement  which 
he  is  not  willing  to  stand  by,  for  once  having  made  an 
unequivocal  promise  in  a  letter,  he  can  not  honorably 
repudiate  his  agreement,  even  if  he  might  legally  do  so. 

5.  Clearness. — A  business  letter  is  worthless  unless  it 
is  understandable.  For  this  reason  it  should  contain  no 
vague  or  ambiguous  statements.  Good  English  is  as 
important  in  a  letter  as  in  any  other  form  of  composition, 
perhaps  even  more  so  since  here  the  evil  results  of  inco- 
herent sentences  are  hkely  to  be  certain  and  immediate. 

6.  Courtesy. — Good  business  relations  can  be  es- 
tablished and  maintained  only  upon  a  basis  of  gentle- 
manly conduct  and  unfailing  courtesy.  Irritation,  pride, 
and  anger  expressed  in  business  letters  are  seldom  war- 


396    COMPOSITION  OF  TECHNICAL  PAPERS 

ranted  and  more  seldom  accomplish  their  ends.  It  is 
well  always  to  remember  the  point  of  view  of  the  other 
man  and  to  treat  him  with  the  dignity  and  decency  which 
you  would  expect  him  to  show  towards  you. 

7.  Dignity. — Courtesy  in  a  business  letter  does  not 
mean  undue  familiarity.  The  average  reader  of  a  busi- 
ness letter  resents  being  addressed  by  a  stranger  or  mere 
business  acquaintance  as  though  he  and  his  correspon- 
dent were  bosom  friends  as  much  as  he  resents  being 
slapped  on  the  back  or  called  ''old  fellow"  by  a  person 
whom  he  has  just  met.  Moreover,  he  is  very  likely  to 
suspect  the  good  taste  or  the  motives  of  such  a  writer. 
A  uniform  tone  of  dignity  and  self-respect  in  business 
letters  is  much  to  be  preferred  to  a  blatant  and  vulgar 
over-desire  to  please. 

8.  Individuality. — The  "personal  touch"  has  become 
a  familiar  phrase  in  business  correspondence.  It  means 
that  the  business  letter  need  not  be  so  formal  and  regular 
as  to  submerge  entirely  the  individuality  of  the  writer. 
It  means  further  that  every  correspondent  likes  to  feel 
that  the  letter  addressed  to  him  is  meant  for  him  and  is 
not  identical  or  almost  identical  with  those  sent  to  scores 
of  others.  A  part  of  this  individuality  may  be  secured 
by  following  the  prevailing  practice  of  avoiding  stock 
phrases  and  formulas,  but  much  of  it  lies  behind  the 
mere  form  and  phrasing,  in  the  personality  of  the  writer. 
The  importance  often  attached  to  this  quality  is  illus- 
trated in  an  incident  which  occurred  not  many  years  ago 
in  the  Broadway  offices  of  a  large  manufacturing  com- 
pany. A  young  Sibley  College  graduate  had  been  for 
two  months  in  charge  of  a  minor  department  which  de- 
manded considerable  correspondence.  He  was  priding 
himself  upon  the  increasing  resemblance  between  his 


BUSINESS  LETTERS  397 

letters  and  those  of  his  predecessor  in  the  position,  and 
was,  therefore,  much  surprised  when  his  chief  said  to 
him  one  morning, 

^'Mr.  Johnson,  what  is  the  matter  with  your  letters? 
I  have  been  reading  some  of  them  lately,  and  they  don't 
suit  me  at  all." 

"Why,  sir,"  was  the  reply,  "I  am  sure  that  they  are 
just  like  those  Mr.  Billings  wrote  before  I  took  charge  of 
his  work." 

"Of  course  they  are,  and  that's  just  what's  wrong  with 
them.  He  is  a  'rubber-stamp'  man,  and  I  thought  when 
I  put  a  college  graduate  in  his  place  that  the  letters  would 
show  a  lot  more  color  and  individuality.  What  is  your 
college  training  good  for?  Now  throw  your  rubber- 
stamp  into  the  scrap-basket,  and  write  me  some  real 
letters." 

Shortly  after  this  incident  the  young  college  man 
epitomized  his  lesson  in  a  letter  to  a  friend  in  the  follow- 
ing words: 

"A  business  letter  should  be  clearly  distinctive  of  the 
writer,  and  its  form  should  vary  constantly,  or  he  will 
get  into  a  rut  and  not  write  a  college  man's  letter.  Rigid 
forms  and  phrases  are  good  enough  only  for  rubber- 
stamp  clerks." 

Form  of  the  Business  Letter 

A  sample  business  letter  arranged  in  accordance  with 
the  best  prevailing  form  is  shown  on  page  398.  For 
convenience  of  reference  the  different  parts  have  been 
numbered  and  labeled.  The  suggestions  for  good  form 
which  follow  should  not  be  regarded  in  all  cases  as  indi- 
cating invariable  practice  but  as  representing  what  an 


398    COMPOSITION  OF  TECHNICAL  PAPERS 

examination  of  several  hundred  business  letters  seems  to 
show  are  the  best  usages. 


[l.   Heading] 
16  Johnson  Court. 
Uadison.  Wlsoonain. 
Hay  6.   1916, 
i2.   Insldo  Address] 
Marshall -Blakemore  Manufacturing  Compamy, 
Milwaukee.  Wisconsin. 

L3.   Salutation] 
Gentlemen: 

14.   Body  of  Letter] 

I  have  been  informed   that  each  year  you  take   into 
your  employ  a  number  of  engineering  college  graduates t 
and   I   should  like,   therefore,   to   file  my  application  for 
a  position  with  you. 

My  practical  experience  consists  of  four  months,   June 
to  September,   1913,  with  Judson  and  Puller,   Consulting 
Chemists,   145  Lambert   Street,    Chicago,   makir^   the  testa 
included  in  their  report  to   the   Association  of  Conmerce 
on  the  abatement  of  the    smoke  nuisance  and  the   electri- 
fication of  the  railway  terminals. 

I  shall  be  graduated   from  the  University  of  VTiscoHslii 
in  June   of  this  year  with   the   degree   of  B.    S.    In  Chemieal- 
Engineering. 

By  permission  I  refer  yon  to  the  following  gentlemen: 

Mr.   William  B.    Judson,   Consulting  Chemist, 
146   Lambert   Street,   Chica.'jo.    Illinois. 

Professor  R.   J.   Bedford.   University   of  Wiaconaln. 
Madison.  Wiaconsin. 

Mr.   Raymond   T.   Hdwards,   Cashier  of   the   Third  Ifational  BaoJk, 
Madison,  Wisconsin. 

If  you  diould  care  to  have  s  personal  interview  with 
oe,   I  can  go.  to  Milwaukee  at  any  tloB  vfaich  saitar^our  oon- 
Tenlenoe. 

[5.    Complimentary  ciloaa) 
Very  truly  yours ► 

L6.   Signature] 
(Sig. )  J.   B.  Adamson. 


I.  Heading. — The  heading  consists  of  the  writer*s 
address,  where  this  is  not  given  in  the  letterhead,  and  the 
date.     Both  address  and  date  are  necessary  and  must  be 


BUSINESS  LETTERS  399 

supplied  in  all  cases.  Omission  of  the  writer's  address 
makes  a  reply  difficult,  if  not  impossible,  and  the  date 
must  be  used  in  interpreting  the  content  of  the  letter. 
In  the  arrangement  of  the  lines  of  the  heading  the  prac- 
tice of  making  the  left  edge  vertical,  as  shown  in  the 
model,  instead  of  slanting  downwards,  seems  to  be  usual. 
Abbreviations  should  ordinarily  not  be  used;  if  they  are 
used,  they  should  conform,  in  the  case  of  states,  with  the 
post-office  regulations  and  in  the  case  of  months  with 
standard  usage.  Dates  should  not  be  abbreviated  as 
follows:  2/5/'i7,  for  February  5,  1917. 

2.  Inside  Address. — The  inside  address  preserves  some 
very  necessary  information  after  the  envelope  has  been 
destroyed.  It  is  needed  for  a  complete  understanding 
of  the  letter  and  sometimes  for  a  correct  fixing  of  respon-  • 
sibilities.  The  title  of  the  person  or  firm  should  be  given 
excepting  where  it  is  regularly  omitted  in  advertising 
and  correspondence  by  the  business  house  addressed; 
e.g.y  Dr.  John  B.  Evans,  Edward  N.  Marshall,  Esq., 
Messrs.  Bolton  and  Smith,  The  Globe  Milling  Com- 
pany. A  letter  addressed  to  a  firm  but  intended  for  an 
individual  member  or  employee  should  be  addressed  as 
follows:  ^ 

The  Globe  Milling  Company,  St.  Paul,  Minnesota, 

Attention:  Mr.  J.  R.  Smith,  Purchasing  Department. 

Practice  differs  in  the  matter  of  indenting  successive 
items  of  the  address  or  of  writing  all  the  same  distance 
from  the  left  hand  margin.  The  latter  practice  saves 
time  in  typewriting,  and  is,  perhaps,  more  frequently 
followed.  In  any  case  the  inside  address  should  conform 
in  this  detail  with  the  heading. 

3.  Salutation. — In  the  best  business  letters  the  follow- 


400    COMPOSITION  OF  TECHNICAL  PAPERS 

ing  forms  are  used  in  the  salutation:  Dear  Sir:  Gentle- 
men: Dear  Madam:  Ladies:.  Sir:  is  usually  used  only 
in  the  government  service  in  addressing  a  superior,  or, 
sometimes,  in  addressing  an  editor.  Dear  Sirs:  is  not  in 
good  usage;  My  dear  Sir:  is  often  condescending  in  its 
implication. 

The  colon  should  be  used  with  the  salutation. 

4.  Body  of  the  Letter. — To  comment  fully  on  the  body 
of  the  letter  would  be  almost  to  give  a  complete  course  in 
business  correspondence  and  in  English  composition. 
What  follows  is,  therefore,  merely  an  attempt  to  empha- 
size certain  essentials. 

{a)  Content. — A  business  letter  should  ordinarily  deal 
with  only  one  subject,  excepting  where  it  is  an  omnibus 
letter  replying  to  several  questions  asked  by  the  corre- 
spondent. The  letter  which  takes  up  more  than  one  sub- 
ject is  difficult  to  file  without  cross-reference  even  if  it 
does  not  have  to  be  sent  from  one  department  to  another 
for  answer.  The  subject  of  the  letter  should  be  defi- 
nitely stated  in  the  first  or  second  sentence.  Sometimes 
it  is  put,  like  the  title  of  an  article,  in  a  separate  caption 
just  under  the  letterhead,  a  practice  which  assists  greatly 
in  filing  and  reference. 

{h)  Paragraphing. — The  usual  principles  of  para- 
graphing do  not  apply  to  the  business  letter.  Here  each 
item  is  for  distinctiveness  paragraphed  separately  so  that 
even  a  comparatively  short  letter  may  have  several  para- 
graphs. For  example,  a  letter  reporting  to  the  shippers 
the  receipt  of  a  damaged  shipment  might  be  paragraphed 
thus: 

Paragraph  i.  Notice  that  shipment  number  so-and-so 
arrived  on  such-and-such  a  date  in  bad  order. 

2.  Description  of  the  extent  of  the  damage. 


BUSINESS  LETTERS  401 

3.  Statement  of  the  probable  responsibility  of  shipper 
or  carrier. 

4.  Statement  of  what  adjustment  the  receiver  of  the 
damaged  shipment  regards  as  satisfactory. 

Other  examples  of  paragraphing  will  be  found  in  the 
specimen  letters  on  pages  409-420. 

(c)  Beginning. — The  initial  sentence  is  as  difficult  to 
write  as  it  is  important.  Unless  the  letter  opens  a  corre- 
spondence, the  first  sentence  should  usually  contain  a 
reference  to  the  date  and  subject  of  the  letter  being 
answered,  or  to  the  telegram,  telephone  message,  con- 
versation, or  other  transaction  which  occasioned  the 
letter.  This  reference  provides  for  the  reader  an  im- 
mediate connection  with  the  subject.  The  first  sentence 
may  also  contain  a  statement  of  the  subject  of  the  letter; 
if  it  does  not,  the  subject  should  almost  always  be  stated 
early  in  the  letter.  Occasionally,  as  in  a  collection  letter, 
the  writer  may  wish  to  approach  the  real  subject  easily 
and  gently;  and  he  will  therefore  begin  with  a  matter  of 
minor  importance  and  gradually  open  into  the  more  im- 
portant matters. 

The  initial  sentence  may  contain  the  necessary  ele- 
ments of  contact  point  and  subject  announcement  with- 
out being  a  stiff  formula.  Formal  beginnings  Hke  the 
following  should  be  avoided: 

*' Yours  of  the  3rd  inst.  at  hand  and  contents  carefully 
noted.     In  reply  would  say,  etc." 

"  Referring  to  your  favor  of  March  6,  etc." 

Beginnings  which  are  more  easy,  graceful,  and  natural, 
like  the  following,  give  the  information  necessary  and  are 
at  the  same  time  much  pleasanter  to  read: 

*'In  reply  to  your  appHcation  of  January  16  for  a 
position  with  us,  we  are  sorry  to  say  that  our  firm  does 


402    COMPOSITION  OF  TECHNICAL  PAPERS 

not  make  a  practice  of  employing  in  its  shops  men  who 
have  not  had  some  experience  in  machine-shop  work, 
etc." 

"After  our  telephone  conversation  of  last  Monday,  I 
immediately  investigated  with  Mr.  Jones  the  condition 
of  the  Briar  Street  Theatre  and  found  the  following  de- 
tails which  do  not  conform  with  the  building  regulations, 
etc.:" 

(d)  Conclusion. — Between  the  initial  and  the  conclud- 
ing sentences  of  a  business  letter,  form  and  content  will 
naturally  depend  largely  upon  the  subject  matter.  At 
the  end  the  best  rule  to  follow  is:  When  through,  stop. 
A  conventional,  meaningless,  and  empty  tailing  off 
should  be  avoided.  This  restriction  applies  particularly 
to  the  formal  participial  phrase  ending,  which  is  at  best 
flat  and  tasteless,  and  which  is  often  bad  in  rhetoric. 
The  addressee  should  not  be  insulted  by  such  a  conclu- 
sion as  "Hoping  that  this  matter  will  be  given  your 
prompt  and  careful  attention,"  (as  though  the  writer 
had  some  doubt),  or  put  under  obligations  by  "Thank- 
ing you  in  advance,  etc.,"  or  simply  irritated  by  "Trust- 
ing to  hear  from  you  at  your  earliest  convenience,"  etc.; 
nor  should  the  writer  "remain"  or  even  "beg  to  remain. " 
The  modern  practice  in  respect  to  all  these  ancient  phrases 
is  to  discard  them  for  good,  plain,  simple  English. 

5.  Complimentary  Close. — The  best  forms  for  the  com- 
plimentary close  are:  "Yours  very  truly,"  or  Very  truly 
yours."  "Respectfully  yours"  may  occasionally  be 
used  in  addressing  a  superior,  and  "Respectfully  sub- 
mitted" in  making  a  report.  "Yours  truly"  is  some- 
what blunt;  "Yours  for  business,"  and  the  Hke,  are 
blatant  and  vulgar. 

6.  Signature. — Little  need  be  said  of  the  signature 


BUSINESS  LETTERS  403 

excepting  that  it  should  be  so  legible  as  to  leave  no  doubt 
as  to  the  identity  of  the  writer.  Where  a  representative 
of  a  firm  signs  a  letter  for  his  company,  the  following 
practice  prevails: 

Danville-Jones  Electric  Power  Company 
By  E.  R.  Jones,  President 

Frequently  the  name  of  the  writer  is  typed  in,  the  sig- 
nature being  made  above,  below,  or  even  through  the 
typing.  This  practice  gives  the  full  name  on  the  carbon 
copy  and  also  insures  a  correct  reading  of  the  signature. 

Practices  and  Phrases  to  be  Avoided  Throughout. — The 
subject  of  the  verb  should  not  be  omitted;  e.g.,  "Re- 
ceived a  call  from  your  representative,  Mr.  Smith, 
yesterday  and  looked  over  some  of  his  sample  fixtures. 
Believe  that  we  could  use  some  of  the  drop-lights,  etc." 

The  participial  endings,  "Hoping  .  .  .  ,"  "Trust- 
ing .  .  .  ,"  "Thanking  you  in  advance  .  .  .  ," 
"Assuring  you  .    .    .   ,"  etc.,  should  not  be  used. 

Abbreviations  should  in  general  be  avoided,  although 
for  the  states,  the  months,  and  in  a  few  other  cases  they 
are  permissible.  The  forms  "ult.,"  "inst,."  and  "prox." 
should  not  be  employed  instead  of  the  specific  name  of 
the  past,  the  present,  and  next  month  respectively. 

The  following  words  and  phrases  should  not  be  em- 
ployed: "We  beg  to  remain;"  ''as  per  your  request;" 
"contents  carefully  noted;"  "enclosed  please  find;" 
"we  note  you  state;"  "each  and  every  one;"  "in  reply 
would  state;"  "yours,"  or  "your  favor,"  for  "your 
letter;"  "advise"  for  "inform;"  "state"  for  "say;" 
"per"  for  "by"  (in  a  signature);  "same"  for  the  specific 
substantive,  and,  in  general,  any  worn-out,  "rubber- 
stamp"  word  or  phrase  which  is  meaningless,  empty, 


404    COMPOSITION  OF  TECHNICAL  PAPERS 

and  colorless,  and  which  can  either  be  omitted  entirely 
without  loss  to  the  letter  or  should  yield  to  a  more  natural 
and  individual  word  or  phrase. 

Types  of  Engineering  Letters^ 

Letters  written  by  employees  of  engineering  companies 
usually  take  three  forms:  (i)  correspondence  of  a  more 
or  less  social  character  between  companies  and  officials 
of  companies,  such,  for  example,  as  invitations,  letters  of 
congratulation,  etc.;  (2)  staff  correspondence  between 
employees  of  the  same  company;  and  (3)  regular  business 
correspondence  with  other  companies  or  with  individuals. 
Of  the  first  class  nothing  will  here  be  said;  of  the  second, 
only  such  comments  will  be  made  as  apply  also  to  letters 
of  the  third  class;  of  the  many  different  types  belonging  to 
the  third  class,  it  will  be  necessary  to  select  for  comment 
only  a  few  of  the  more  common.  These  comments  will 
be  preceded  by  a  fuller  comment  on  the  letter  of  applica- 
tion, the  type  with  which  students  are  usually  most 
concerned. 

I.  Letters  of  Application. — The  letter  of  application  is 
usually  the  first  type  of  business  letter  which  the  engineer- 
ing college  graduate  is  required  to  write.  Most  engineer- 
ing concerns  request  the  filling  out  of  an  application 
blank,  but  the  original  letter  applying  for  the  position 
is  filed  and  is  in  many  cases  important ;  it  should  therefore 
be  carefully  written.  The  letter  of  application  should 
ordinarily  contain  the  following  elements:  {a)  point  of 
contact;  {h)  application  for  the  position;  (c)  statement  of 

iPor  much  of  the  specific  information  in  this  section  acknowledgment 
is  made  to  Mr.  P.  W.  Kinney  of  Rochester.  N.  Y.,  and  to  Mr.  H.  W. 
Watt  of  the  Westchester  Lighting  Company,  Mt.  Vernon,  N.  Y. 


BUSINESS  LETTERS  405 

qualifications  and   experience;    (d)   references;   and   (e) 
arrangement  for  personal  conference. 

(a)  Point  of  Contact. — This  begins  the  letter  with  a 
statement  of  the  source  of  information  regarding  the 
vacancy  or  possible  opening;  e.g.,  "In  response  to  your 
advertisement  in  yesterday's  Herald  for  a  skilled  me- 
chanic, etc.;"  "I  learned  yesterday  from  Mr.  G.  E.  Ed- 
wards, foreman  of  the  Repair  Department  of  the  Duluth 
Motor  Works,  that  you  have  a  vacancy  in  your  machine- 
shops,  etc." 

(b)  Application  for  the  Position. — The  applicant  should 
not  fail  to  say  definitely — as  he  is  frequently  likely  to 
do — that  he  is  an  applicant  for  the  position.  This  state- 
ment should  usually  be  combined  with  the  sentence  con- 
taining the  point  of  contact. 

(c)  Statement  of  Qualifications  and  Experience. — In  this 
section  of  the  letter  the  writer  should  be  modest  but  not 
self-depreciatory,  A  dignified,  impersonal  statement  of 
those  qualifications  which  the  prospective  employer 
should  know  and  which  would  prove  useful  in  the  posi- 
tion applied  for  can  not  fail  to  be  more  impressive  than 
statements  which  are  either  conceited  or  self-consciously 
over-modest.  The  writer  should,  on  the  one  hand,  give 
a  sufficiently  complete  statement  of  qualifications,  but 
should,  on  the  other  hand,  avoid  the  self-sufficient  infla- 
tion often  embodied  in  the  familiar  "I  feel  fully  qualified 
to  fill  the  position." 

(d)  References. — A  good  list  of  references  is  more  im- 
portant than  the  applicant  usually  realizes.  The  list 
should  possess  variety  so  that  while  some  may  vouch 
for  the  applicant's  technical  knowledge  and  experience, 
others  may  certify  to  his  general  moral  qualifications. 

The  applicant  should  not  list  persons  who  have  not  ex- 
26 


4o6    COMPOSITION  OF  TECHNICAL  PAPERS 

pressed  their  willingness  to  be  written  to  concerning 
him,  and  he  should  avoid  listing  persons  of  prominence 
or  influence  who  are  but  slightly  acquainted  with  him. 
For  the  reader's  convenience  each  reference  should  begin 
a  new  paragraph.  The  enclosure  of  open  letters  of  re- 
commendation collected  from  friends  and  teachers  is  of 
little  value;  letters  of  recommendation  should  not  pass 
through  the  hands  of  the  applicant. 

(e)  Arrangement  for  a  Personal  Conference. — Where  a 
personal  conference  is  expected  or  desirable,  the  applicant 
may  suggest  that  he  can  arrange  to  meet  his  prospective 
employer  at  a  time  to  suit  the  latter's  convenience. 
He  should  never  attempt  to  set  the  exact  time  of  the  con- 
ference; this  is  the  privilege  of  the  person  addressed. 
The  applicant  may,  however,  write  somewhat  as  follows: 
"I  expect  to  be  in  Chicago  next  Thursday  afternoon,  and, 
if  convenient  for  you,  I  can  arrange  to  meet  you  at  that 
time." 

The  appearance,  care,  and  tone  of  a  letter  of  applica- 
tion are  usually  of  as  much  importance  as  strong  qualifi- 
cations. A  slovenly,  careless  letter,  filled  with  errors,  con- 
demns the  applicant  before  the  reader  reaches  the  state- 
ment of  the  writer's  experience.  A  letter  of  application 
should  be  comparatively  brief;  a  long-winded  self-glori- 
fication amuses  the  reader  even  if  it  does  not  irritate  him. 
Finally,  the  letter  should  be  individual;  no  "model" 
should  be  followed  rigidly.  Of  several  hundred  letters 
of  application  written  recently  in  a  state  civil  service 
examination  all  but  half  a  dozen  were  almost  identical 
save  for  the  data  which  they  contained;  and  the  half 
dozen  stood  out  from  the  others  because  they  revealed 
personalities  behind  the  written  page. 


BUSINESS  LETTERS  407 

2.  Order  Letters, — The  order  letter  should  usually 
contain:  (a)  the  order;  (b)  shipping  directions,  where 
they  are  not  already  definitely  understood;  (c)  date 
when  goods  are  wanted;  (d)  arrangements  for  remittance, 
where  this  matter  has  not  been  previously  agreed  upon. 
To  facilitate  checking,  the  list  of  goods  should  be  tabu- 
lated, with  each  item  on  a  separate  line.  For  emphasis 
each  item  should  be  capitalized.  The  order  should  be 
carefully  checked  over  before  it  is  mailed,  and  a  copy  of 
it  should  invariably  be  kept. 

3.  Adjustment  Letters. — If  a  shipment  is  delayed  or 
received  in  bad  order,  or  if  a  guaranteed  machine  breaks 
down  or  proves  on  test  to  be  below  specifications  in  the 
contract,  the  person  inconvenienced  thereby  should  not 
blame  the  shipper  or  contractor  in  an  angry  letter,  but 
should  simply  lay  before  him  the  facts  in  the  case  with 
perhaps  a  suggestion  as  to  what  adjustment  will  be 
satisfactory  to  the  purchaser.  In  reply  the  writer  should 
express  regret  at  the  annoyance  which  his  correspondent 
has  suffered  and  promise  such  adjustment  as  the  facts 
may  warrant. 

4.  Letters  of  Instruction. — ^Letters  of  instruction  may  be 
addressed  to  subordinates  delegated  to  carry  out  certain 
operations  or  to  customers,  consumers,  or  others  not 
ofiScially  connected  with  the  company.  All  such  letters 
must  be  absolutely  clear.  In  the  case  of  letters  of  in- 
struction to  outsiders  the  lack  of  technical  knowledge 
of  the  readers  must  usually  be  taken  into  account  as 
well  as  their  peculiar  relationship  with  the  writer  or  with 
the  company  which  he  represents.  An  individual  who 
has  purchased  from  a  manufacturing  concern  a  machine 
which  he  is  having  some  operating  difficulties  with  ex- 
pects and  is  entitled  to  a  painstaking  explanation  of 


4o8    COMPOSITION  OF  TECHNICAL  PAPERS 

his  troubles  and  clear  and  complete  directions  for  over- 
coming them. 

5.  Letters  of  Commendation. — Practicing  engineers  are 
frequently  asked  to  write  their  opinion  concerning  men, 
engineering  practices,  and  apparatus  of  various  sorts. 
In  writing  a  letter  of  recommendation  for  an  individual, 
the  writer  should  be  fair  but  just;  he  should  write  exactly 
what  he  believes  to  be  the  qualifications  of  the  individual 
for  the  particular  position  involved,  and  his  opinion 
should  be  based  solidly  on  experience  with  the  subject 
of  the  letter  and  observations  of  his  work.  A  comment 
on  a  technical  practice  or  piece  of  apparatus  should  state 
the  experience  of  the  writer  with  the  apparatus,  his 
belief  as  to  the  limits  of  its  usefulness,  and  of  its  particular 
adaptability  to  the  work  in  which  it  is  proposed  to  use  it. 
The  length  of  a  letter  of  commendation  will  be  dependent 
upon  the  subject;  but  no  such  letter  should  fail  to  con- 
tain details  which  the  reader  would  be  interested  in  or 
likely  to  find  useful. 


BUSINESS  LETTERS  409 


SPECIMEN  LETTERS 

[The  following  selection  of  letters  is  not  intended  to 
be  completely  representative  of  all  types;  they  are  de- 
signed merely  to  provide  material  for  class  criticism, 
and  should  be  supplemented  by  other  student  and  pro- 
fessional letters.  The  student  letters  here  reproduced 
were  submitted  as  "themes"  in  a  regular  course;  the 
professional  letters  were  taken  from  the  files  of  a  large 
engineering  company,  only  such  changes  in  names  being 
made  as  were  necessary  to  conceal  identities.  It  need 
hardly  be  added  that  the  letters  are  not  all  "models".] 

Student  Letters 

(i) 

1354  Orchard  Street, 
Madison,  Wisconsin, 
May  6,  1916. 

Mr.  W.  S.  Holmes,  Gen.  Mgr., 

Merryviile  Electrical  Works, 

Merry ville,  Illinois. 

Dear  Sir: 

I  am  looking  for  a  position  in  the  Testing  Department  of  Elec- 
trical Machinery,  and  wish  to  know  if  you  have  such  a  position 
open  at  the  present  time.  I  am  especially  desirous  of  getting  the 
practical  experience  in  the  testing  of  Motors  and  Generators. 

I  have  completed  three  years  in  the  Electrical  Engineering  Course 
at  the  University  of  Wisconsin,  and  I  am  fairly  well  informed  on 
the  electrical  design  and  construction  of  the  machines  which  you 
manufacture.  I  have  had  one  year  of  machine  work  in  the  Holt 
Machine  Company  of  this  city. 

I  should  be  glad  to  hear  from  you  or  to  arrange  an  appointment 
at  your  convenience. 

Respectfully  yours, 
(Sig.)  L.  M.  Kendall. 


4IO    COMPOSITION  OF  TECHNICAL  PAPERS 

(2) 

638  Riverside  Avenue, 
Madison,  Wisconsin, 
May  IS,  1916. 

Wisconsin  Highway  Commission, 

Madison,  Wisconsin. 

Gentlemen:   . 

I  have  learned  through  Professor  T.  M.  Edwards  of  this  city  that 
there  will  probably  be  a  vacancy  on  your  force  in  the  near  future, 
and  I  wish  to  offer  myself  as  an  applicant  for  the  position. 

I  graduated  three  years  ago  from  the  University  of  Wisconsin  in 
the  Civil  Engineering  Course,  and  since  my  graduation  I  have  had 
two  years'  experience  in  the  main  drafting  room  of  the  Southern 
Minnesota  Public  Service  Company,  and  in  addition  I  have  been 
with  the  Vilas  County  (Wisconsin)  Road  Commission,  with  head- 
quarters at  Vilas,  for  one  year.  During  this  last  period  I  did  all 
manner  of  instrument  work,  in  the  field,  together  with  map  making 
and  topography  work. 

Mr.  R.  L.  Lamson  of  Vilas  has  expressed  himself  as  being  willing 
to  recommend  me;  and  I  am  also  permitted  to  refer  you  to  Mr. 
M.  I.  Maxon,  Superintendent  K.  L.  P.  S.  Co.,  Terminal  Building, 
Chicago,  Illinois. 

My  address  is  638  Riverside  Avenue.  I  shall  be  glad  to  keep 
an  appointment  at  any  time  that  may  be  convenient  to  you. 

Yours  truly, 
(Sig.)  N.  C.  Hubbard. 

(3) 

In  answering,  please 

refer  to  No.  7576. 

198  College  Place, 
Madison,  Wisconsin, 
May  25,  1916. 

E.  H.  Sudham  and  Company, 

1476  South  Park  Avenue, 

Chicago,  Illinois. 

Gentlemen: 

Please  send  me  at  once  via  American  Express,  charges  prepaid, 
the  following: 


BUSINESS  LETTERS  411 


No.     Size. 

Kind. 

Cat.  No. 

Price. 

Total  Price. 

1 2-  500  cc. 

Jena  Beakers 

555B  at 

$.18 

$2.16 

24-  250  cc. 

Jena  Beakers 

557B  at 

$.16 

$3  84 

6-1000  cc. 

Erlemeyer  Flasks 

768E  at 

$.21 

$1.26 

6-  500  cc. 

Distillation  Flasks 

446D  at 

$•35 

$2.10 

12-  100  cc. 

Volumetric  Flasks 

504V  at 

$.25 

$3.00 

12-     50  cc. 

Pipettes 

223P  at 

$.15 

$1.80 

36-     25  cc. 

Pipettes 

224P  at 

$.15 

$5.40 

Total         $19.56 

As  heretofore,  if  goods  are  received  in  good  condition,  we  will 
send  you  our  check  for  $19.56  within  ten  days  of  date  of  receipt  of 
shipment. 

Very  truly  yours, 
Madison  Chemical  Works, 
By  (Sig.)  T.  L.  Lund, 
Manager. 


(4) 

1397  Erin  Avenue, 
Madison,  Wisconsin, 
April  30,  191 5. 

Iowa  Brass  Company, 

Mansfield,  Iowa. 

Gentlemen: 
Please  ship  us  the  following  items  by  way  of  the  C.  E.  and  I.: 
•  75  No.  8648  Side  Bearing  Sheradized  Insulators. 
150  No.  7554 — 12"  Uninsulated  Sheradized  Turnbuckles. 
24  No.  1080  Malleable  Iron  Untreated  Mine  Hangers  for  550 
volts. 

We  must  have  the  Hangers  by  May  15  and  the  other  items  by 
May  20.  We  will  honor  a  draft  drawn  to  your  order  for  the  amount 
of  the  shipment  in  full  on  May  12. 

Very  truly  yours, 
Madison  Electric  Company, 
By  (Sig.)  John  K.  Parsons, 
Purchasing  Agent. 


412    COMPOSITION  OF  TECHNICAL  PAPERS 

(5) 

1397  Erin  Avenue, 
Madison,  Wisconsin, 
May  12,  1915. 

Iowa  Brass  Company, 

Mansfield,  Iowa. 

Gentlemen: 

We  have  received  your  notice  of  May  7  of  the  shipping  of  order 
E97403  to  us  over  the  C.  E.  and  I.,  but  we  have  not  as  yet  received 
the  bill  of  lading  from  the  railroad  company. 

There  has  evidently  been  some  delay  in  this  shipment,  and  we 
should  appreciate  your  cooperation  in  tracing  these  articles. 

Very  truly  yours, 
Madison  Electric  Company, 
By  (Sig.)  John  K.  Parsons. 
Purchasing  Agent. 


(6) 

1397  Erin  Avenue, 
Madison,  Wisconsin, 
May  IS,  1915. 

Iowa  Brass  Company, 

Mansfield,  Iowa. 

Gentlemen: 

The  shipment  of  order  E97403  was  delivered  to  us  to-day  by  the 
C.  E.  and  I.  R.  R.  Company,  and  in  checking  over  the  items  we 
have  found  that  25  of  the  No.  7554-12  in.  Uninsulated  Sheradized 
Turnbuckles  have  defective  threads  on  at  least  one  end. 

Inasmuch  as  the  boxes  which  contained  the  articles  were  received 
in  good  order,  it  would  appear  that  the  trouble  is  in  the  manufacture 
and  inspection  rather  than  in  any  damage  incurred  in  transportation. 
If  you  will  check  this  matter  up  by  your  inspection  records  and 
inform  us  as  to  the  cause  of  the  defect  and  as  to  the  adjustment 
which  you  are  prepared  to  make,  we  shall  appreciate  it. 

Yours  very  truly, 
Madison  Electric  Company, 
By  (Sig.)  John  M.  Perry, 
Receiving  Department. 


BUSINESS  LETTERS  413 

(7) 

Mansfield,  Iowa, 
May  18,  1915. 

Madison  Electric  Company, 

1397  Erin  Avenue, 

ATTENTION:  MR.  JOHN  M.  PERRY. 

Madison,  Wisconsin. 

Gentlemen: 

We  are  very  sorry  to  learn  from  your  letter  of  May  15  that  the 
Turnbuckles  which  we  shipped  you  on  order  No.  97403  were  de- 
fective. 

Upon  checking  up  our  records  we  have  found  that  your  order  of 
Turnbuckles  was  filled  from  a  mixed  lot  which  had  not  been  in- 
spected. This  mistake  was  due  to  the  crowded  condition  of  our 
stock  room,  which  is  being  rearranged. 

We  regret  exceedingly  that  we  have  caused  you  this  annoyance, 
and  consequently  we  are  shipping  you  by  express  to-day  25  No. 
7554-12  in.  Uninsulated  Sheradized  Turnbuckles. 

Very  truly  yours, 
Iowa  Brass  Company, 
By  (Sig.)  M.  K.  Nimms, 
Adjustment  Department. 

Professional  Letters 

A.  Staff  Correspondence. 

(8) 

[Letterhead] 


Reply  to  Letter  of  .  . .  . 
Referring  to  Meadville. 


Mr.  H.  W.  Washburne,  Cadet  Engineer, 
BUILDING. 


Livingston,  N.  J. 
Nov.  5,  1914. 


Dear  Sir: 

I  wish  you  would  arrange  to  inspect  overhead  lines  in  the  Mead- 
ville District  with  a  view  to  ascertaining  the  number  and  height  of 
poles;  number  of  cross  arms  on  each  pole;  number  and  size  of  trans- 


414    COMPOSITION  OF  TECHNICAL  PAPERS 

formers;  number  and  type  of  incandescent  and  arc  street  lighting 
fixtures;  number  of  lighting  arresters,  etc. 

In  other  words,  we  want  to  take  an  inventory  of  all  overhead 
line  construction  including  ground  plates,  ground  pipe,  and  light- 
ning arrester  wiring. 

Yours  truly, 

(Sig.)  F.  M.  Mason, 
Engr.  Elec.  Dept. 
FMM/G      - 

(9) 

[Letterhead] 

Livingston,  N.  J. 
Dec.  24,  1910. 
work  order  3345. 

Mr.  G.  H.  Banfield,  Supt., 

Meadville. 
Dear  Sir: 

In  connection  with  work  order  3345  completed  Nov.  18,  iqio, 
our  inspector  reports  that  the  primary  tap  on  Dodge  Lane  has  been 
taken  from  the  Emsley  Heights  circuit.  This  should  be  cut  onto 
the  Kendall  circuit.  He  also  reports  that  the  transformer  pole  is 
not  stepped. 

Will  you  kindly  see  that  this  work  is  done  and  notify  this  oflSce 
when  it  is  completed. 

Yours  truly, 
(Sig.)  D.  M.  Thomas, 
Engr.  El.  Distribution. 
DMT/G 

(10) 

[Letterhead] 

Livingston,  N.  J. 
H.  T.  Insulators.  December  i,  191 2. 

Mr.  Raymond  Ulrich,  Asst.  E.  E.  D. 

Building. 
Dear  Sir: 

500  H.  T.  insulators  received  from  the  Ohio  Brass  Co.  on  order 
62722  were  inspected  to-day  and  disposition  made  as  follows: 


BUSINESS  LETTERS  415 

Accepted 494 

Rejected  (off  color) 3 

(broken) i 

"         (cracked) i 

"         (pin  hole  too  small) i 

Total SCO 

As  there  are  only  three  of  the  total  number  which  can  not  be 
used,  I  would  recommend  that  the  entire  consignment  be  accepted. 

Yours  truly, 
(Sig.)  T.  R.  Lane, 
TRL/K  Inspector. 

(11) 

[Letterhead] 
Req.  1807  WP  Livingston,  N.  J. 

Ext. — St.  Mary's  Hospital.  April  13,  1915. 

Mr.  Edward  Wildman, 
Chief  Electrical  Engineer, 
BUILDING. 
Dear  Sir: 

The  attached  requisition  calls  for  changes  in  the  line  on  private 
property  of  St.  Mary's  Hospital. 

As  explained  to  me  by  Mr.  Holmes,  the  buildings  are  being  re- 
wired, and  St.  Mary's  Hospital  has  requested  the  Company  to 
bring  an  additional  service  into  the  school  building,  which  is  at 
present  connected  by  an  underground  from  the  hospital.  This 
change  will  give  them  better  service,  which  at  present  is  poor  on 
account  of  their  inefficient  wiring. 

If  carried  out,  the  changes  will  require  one  pole  to  be  set  on 
private  property. 

In  view  of  the  fact  that  the  hospital  has  been  seriously  consider- 
ing the  installation  of  a  private  plant,  Mr.  Holmes  is  very  anxious 
that,  if  possible,  the  suggested  change  be  put  through  without 
any  cost  to  the  hospital.  Ordinarily  the  charge  would  be  $15.00 
for  the  one  pole  on  private  property. 

Yours  very  truly, 
(Sig.)  E.  R.  Snyder, 
ERS/KLW  Engr.  El.  Distribution. 


4i6    COMPOSITION  OF  TECHNICAL  PAPERS 
B.  Outside  Correspondence. 

(12)  • 

ILetterhead] 
Pot  heads.  Livingston,  N.  J. 

R.  and  G.  Elect.  Specialty  Co.,  December  5,  1915. 

196  West  Johnson  Street,  Chicago,  III. 
Gentlemen : 

Please  quote  us  on  pot  heads  as  follows: 

2— Type  "M  S"  two  conductor. 
2 — Type  "M  C"  two  conductor. 
Compound  for  filling  pot  heads. 

Above  pot  heads  for  use  on  duplex  No.  o  B  and  S  submarine 
cable;  diameter  1%  in.  over  lead  sheath.  Armoured  with  No. 
6  B  and  S  steel  wire.     Working  voltage  2300. 

Also  kindly  advise  weight  of  pot  heads  and  earliest  possible  date 
shipment  can  be  made  after  receipt  of  order. 

In  using  the  above  type  pot  heads  on  submarine  cables  is  it 
customary  to  run  the  cable  with  the  armour  on  into  the  pot  head, 
or  to  cut  back  the  armour  so  that  it  does  not  pass  through  the 
lower  opening? 

Yours  very  truly, 
(Sig.)  C.  N.  Bates. 
CNB/H  Eng.  Elect.  Dept. 

(13) 
[Letterhead] 

ATTENTION  MR.  TUCKER 
QUOTATION  New  York,  November  22,  191 2. 

Livingston  Lighting  Company, 
Livingston,  N.  J. 
Gentlemen: 

Confirming  our  telephone  quotation  of  yesterday,  we  can  furnish: 

10,000  ft.     Twisted  pair  14  B  and  S  telephone  wire,  each  conductor 

rubber  insulated  to  ^^2"  diameter,  separately  braided, 

one  of  the  conductors  to  have  a  raised  thread  to  serve 

as  a  tracer,  at $14.75  M.  ft. 

Net  f.o.b.  cars,  Livingston,  N.  J. 


BUSINESS  LETTERS  417 

Terms:  1%  cash  ten  days,  or  thirty  days  net. 

It  is  understood  that  this  price  is  for  estimating  purposes  only. 

We  hope  to  hear  from  you  further  in  this  connection. 

Yours  very  truly, 
New  York  Wire  and  Cable  Co., 
Sales  Department, 
ORA-DFT  By  (Sig.)  O.  R.  Ames. 

(14) 

[Letterhead] 

Livingston,  N.  J. 
November  14,  1914. 
Mr.  C.  B.  Stover,  Engr.  of  Surveys, 
Danville  Elec.  Light  and  Pr.  Co., 
Danville,  N.  J. 
Dear  Sir: 

In  compliance  with  your  telephone  request  of  this  morning  I 
am  sending  you  some  information  relative  to  pipe  thawing.  All 
of  this  information  was  compiled  during  the  winter  of  191 2-13 
as  last  winter  we  had  no  cases  of  trouble  with  frozen  pipes.  I 
hope  that  this  information  will  be  of  use  to  you. 

If  you  have  any  similar  information  which  you  think  we  might 
be  able  to  use,  I  should  appreciate  it  if  you  will  let  me  have  some 
of  it. 

Yours  very  truly, 
(Sig.)  T.  K.  Simpson, 
TKS/NIF  Supt.  Repair  Dept. 

End.  No.  19266 

(is) 


[Letterhead] 


New  York,  Nov.  3,  191 2. 


J.  S.  Miles,  Esq., 

Electrical  Department, 

Livingston  Lighting  Company, 
Livingston,  N.  J. 

Dear  Sir: 

In  accordance  with  our  conversation  of  this  date  this  is  to 
inform  you  that  both  ends  of  the  3  conductor  paper  insulated 


4i8    COMPOSITION  OF  TECHNICAL  PAPERS 

cable  which  we  are  making  up  on  order  for  you,  the  outside  diame- 
ter of  which  we  estimate  to  be  about  1-28/32",  should  be  pro- 
tected either  by  end  bells  or  lead  pot  heads.  It  is  my  understand- 
ing that  both  ends  of  the  cable  will  be  indoors,  and  if  this  is  the 
case,  you  can  have  pot  heads  formed  by  a  competent  jointer  or 
a  first-class  plumber  using  pieces  of  lead  pipe  measuring  3  to  4" 
in  diameter,  ^^"  thick  and  approximately  12"  long.  One  end  can 
be  rounded  into  a  diameter  of  about  i — 28/32";  the  other  end 
can  be  flared  out  to  4  or  5"  in  diameter,  the  diameter  depending 
upon  th6  piece  of  pipe  used. 

Three  single  rubber  cables  should  be  soldered  to  the  paper 
conductors  in  such  a  way  that  they  will  be  inside  the  pot  head, 
well  separated  from  one  another  when  the  lead  pot  head  is  drawn 
into  place  and  a  joint  wiped  on  the  cable.  The  same  can  then 
be  filled  with  hot  paraffine,  and  the  loss  due  to  the  16  per  cent, 
shrinking  of  the  paraffine  on  cooling  can  be  taken  care  of  by  a 
second  or  third  pouring.  If  one  end  of  the  cable  is  to  be  used 
under  less  favorable  conditions  than  above  assumed,  we  would 
recommend  the  use  of  T.  and  N.  pot  heads  as  the  cheapest  satis- 
factory form  of  pot  head  we  know  of.  For  your  information  we 
would  say  that  you  may  reasonably  expect  a  quart  of  paraflSne, 
which  will  measure  about  58  cu.  in.  to  weigh  a  trifle  under  2  lbs. 

We  shall  be  glad  to  furnish  any  additional  information  you  may 
desire. 

Very  truly  yours. 
New  York  Wire  and  Cable  Co., 
By  (Sig.)  R.  B.  Adams, 
RBA/DHO  Engineer. 

(16) 
[Letterhead] 
Dec.  2,  1914.  Livingston,  N.  J. 

Meadville  Trans.  Line.  Dec.  6,  1914. 

Mr.  S.  F.  Sanborn,  D.  P.  Supt. 
Summit  Telephone  Co., 
Summit,  N.  J. 

Dear  Sir: 

The  subject  of  new  transmission  line  at  Meadville  was  taken 
up  in  detail  with  Mr.  Murphy,  and  it  was  decided  that  we  should 


BUSINESS  LETTERS  419 

obtain  and  turn  over  to  the  Telephone  Co.,  certain  rights  of  way 
on  the  East  side  of  Bound  Brook  Rd.,  in  order  that  our  lines  might 
have  the  west  side.     This  has  been  done. 

In  regard  to  the  line  on  New  Broadway  between  Prospect  Ave. 
and  Ashland  St.,  it  was  explained  that  we  had  been  unable  to 
obtain  the  right  of  way  on  the  west  side  of  New  Broadway  in  front 
of  the  Hammond  Estate  and  would  therefore  be  obliged  to  rebuild 
our  line  on  the  east  side  (for  about  three  poles).  In  order  to  separ- 
ate our  lines  at  this  point,  it  will  be  necessary  for  the  Telephone 
Co.  to  transfer  its  interests  from  the  east  to  the  west  side  of  the 
street;  and  in  order  to  facilitate  this  we  are  willing  to  stand  the 
expense  of  making  the  change  and  to  transfer  to  the  Telephone 
Co.  our  poles  Nos.  12,  13,  and  14  on  the  west  side  of  New  Broadway 
and  obtain  a  right  of  way  for  one  other  pole  on  the  north-west 
corner  of  Broadway  and  New  Broadway.  This  is  the  best  arrange- 
ment we  are  able  to  make  at  this  time. 

Yours  very  truly, 
(Sig.)  D.  B.  Abbott, 
DBA/HP  Engr.  Elec.  Dept. 

(17) 

[Letterhead] 

St.  Louis,  U.  S.  A. 
February  26,  1916. 
Dictated 

February  25,  1916. 
Livingston  Lighting  Company, 
Eighth  Ave.  and  First  St., 
Livingston,  N.  J. 

Attention  of  Mr.  H.  L.  Lincoln,. 
Engr.  Elec.  Dist. 
Gentlemen: 

Some  time  ago  Mr.  W.  M.  Helm,  our  Eastern  District  Manager, 
gave  you  copies  of  our  Fuse  Switch  Agreement  which  will  allow 
you  the  maximum  discount  on  Williams  Fuse  Switches  furnished 
in  quantities;  that  is,  if  you  purchase  them  in  smaller  quantities, 
as  soon  as  your  purchases  amount  to  100  Williams  Fuse  Switches, 
a  rebate  will  be  issued  to  you  making  the  cost  $11.50  per  Switch 


4 2o    COMPOSITION  OF  TECHNICAL  PAPERS 

instead  of  the  lower  quantity  price,  and  as  soon  as  your  purchases 
reach  the  200  mark,  an  additional  rebate  will  be  issued  to  you  to 
bring  the  cost  to  $10.00  each. 

When  you  consider  the  fact  that  Williams  Fuse  Switches  combine 
in  one  device  the  advantages  of  a  line  disconnecting  Switch  and  a 
Primary  Fuse  Block  and  none  of  the  disadvantages,  you  can 
readily  see  that  your  saving  in  the  long  run  will  be  much  greater. 
One  of  the  most  important  things  to  be  considered  is  the  mainte- 
nance expense  of  your  overhead  devices.  The  only  item  of  expense 
in  a  Williams  Fuse  Switch  is  re-fusing,  and  this  cost  is  but  2  cents 
per  fuse.  Certainly  in  the  course  of  a  few  years  Williams  Fuse 
Switches  will  have  paid  for  themselves  alone  in  the  saving  of 
re-fusing. 

We  hope,  Mr.  Lincoln,  that  you  will  see  your  way  clear  to  execute 
this  Agreement  and  hope  to  be  in  receipt  of  orders  from  you  for 
Williams  Fuse  Switches,  which,  we  assure  you,  will  have  our  prompt 
attention. 

Yours  very  truly, 
W.  B.  WILLIAMS  AND  BROTHER,  INC. 
MLP:MCT  (Sig.)  M.  L.  Parker, 

WMH  SALES  DEPARTMENT. 


INDEX 

(The  contents  of  reprinted  articles  have  not  been  indexed.) 


Abbreviations,  in  business  letters,  399 
Abstracts,  in  report  writing,  357;  example  of,  378-379 
Accuracy,  in  report  writing,  351-352;  in  business  letters,  395 
Adjective,  defined,  81-82,  86 
Adjective-phrase,  defined,  82,  87 
Adjustment  letters,  400-401,  407 
Adverb,  defined,  82,  86;  misplaced,  115 
Adverb-phrase,  defined,  82-83,  87 

Alvord,  John  W.,  How  to  Use  the  Technical  Journal,  281-289 
American  Institute  of  Electrical  Engineers,  quotation  from  Sug- 
gestions to  Authors,  28,  47 
American  Pedometer,  The,  student  theme  in  technical  description, 

157 
Analysis  of  the  problem,  in  report  writing,  350-351 
Apostrophe,  use  of,  96 
Appearance,  of  business  letters,  393-394 
Application,  letters  of,  404-406 

Argumentation,  defined,  9;  employed  in  technical  description,  156 
Arrangement  of  material,  in  the  whole  composition,  25-44;  in  the 

paragraph,  62-69 
Atka  Model  Canoe,  The,  student  theme  in  technical  description, 

165-166 
Authority,  use  of,  in  expositions  of  ideas,  258-260 

B 

Basement  of  the  Chemical  Engineering  Building,  The,  student  theme 

in  technical  description,  166-167 
Batch  vs.  Continuous  Concrete  Mixers,  student  theme  in  technical 

description,  1 61-163 

421 
27 


42  2  INDEX 

Bee  Exposure  Meter,  student  theme  in  technical  description,  153-154 

Belief,  expositions  of,  2575 

Boiler  Inspection  Report,  student  report,  374-375 

Brevity,  in  report  writing,  352-353;  in  business  letters,  394-395 

Brooks,  Benjamin,  The  Web-Joot  Engineer,  297-308 

Bureau  of  Mines,  reprinted  outlines  and  extracts  from  technical 

papers  of,  41-42,  379-385 
Business  letters,  principles  of,  392-408;  specimens  of,  409-420 
Business  Man  and  the  College  Man,  The,  student  theme  in  expo- 
sition of  ideas,  275-276 


Carefulness,  in  business  letters,  395 

Carty,  John  J.,  Telephone  Service  in  America,  317-^35 

Causes  of  Cracking  of  Cement  Grouted  Brick  Pavements,  student 

theme  in  exposition  of  ideas,  267-268 
Charging  an  Iron  Foundry  Cupola,  student  theme  in  exposition  of 

processes,  207-208 
Chemical  Engineer,  The,  student  theme  in  exposition  of  ideas,  274- 

275 
Clark,  H.  H.,  The  Factor  of  Safety  in  Mine  Electrical  Installations, 

outline  of,  42 
Clause,  defined,  83;  adjective-clause,  83-84,  87;  adverb-clause, 

83-84,  87;  relative  clause,  84;  principal  and  subordinate,  84; 

dependent  and  independent,  87;  dangling  elliptical,  109-110 
Clearness,  in  report  writing,  354;  in  business  letters,  395 
Coherence,  of  the  whole  composition,  25-44;  of  the  paragraph,  62- 

69;  of  the  sentence,  101-123 
Colon,  use  of,  89-95;  with  salutation  in  business  letters,  400 
Comma,  use  of,  89-95;  comma  fault,  91 
Commendation,  letters  of,  408 
Commercial    correspondence,    principles    of,    392-408;    specimen 

business  letters,  409-420 
Comparative  Tests  of  Run-of-Mine  and  Briquetted  Coal  on  the  Tor- 
pedo Boat  Biddle,  Walter  T.  Ray  and  Henry  Kreisinger, 

table  of  contents  of,  379-380 
Comparisons,  in  technical  description,  1 50-1 51 
Completeness,  in  reports,  352;  in  business  letters,  395 
Complex  sentence,  defined,  84,  87 


INDEX  423 

Complimentary  close,  in  business  letters,  402 

Compound  sentence,  defined,  84,  87 

Conciseness,  as  an  element  of  style,  51-52 

Conclusions,  in  general,  49-51;  in  business  letters,  402-403 

Concrete  Mixing  Plant,  A,  student  theme  in  technical  description, 

163-165 
Concreteness,  value  of,  16;  as  an  element  of  style,  51 
Conference,  arrangements  for,  in  letters  of  application,  406 
Construction  of  a  Large  Reflecting  Telescope,  The,  exposition  of  a 

process  by  George  Ellery  Hale,  233-241 
Convenient  Method  for  Replacing  Series  Incandescent  Street  Lamps, 

A,  technical  description  from  Electrical  World,  168-170 
Coordination,  in  sentences,  101-104 
Cope,  Willard  C.  and  Snelling,  W.  O.,  Rate  of  Burning  of  Fuse,  as 

Influenced  by  Temperature  and  Pressure,  outline,  41,  and  first 

part  of,  381-385 
Courtesy,  in  business  letters,  395-396 
Cross-bending  Test  of  a  Wooden  Beam,  student  report  366-367 


Dangling  modifiers,  107-112 

Dash,  use  of,  95 

Dates,  form  of,  in  business  letters,  399 

Definition,  in  technical  description,  154-155;  of  terms,  in  exposi- 
tion of  ideas,  266;  of  writer's  position,  in  exposition  of  ideas, 
266;  of  problem,  in  report  writing,  348 

Dells  of  the  Wisconsin,  student  report,  375-376 

Description,  artistic,  defined,  9;  technical,  principles  of,  26,  146^ 
157;  in  combination  with  exposition  of  processes,  202-203 

Diagramming,  examples  of  sentence;  81-85 

Diagrg,ms,  in  general,  17-19;  in  technical  description,  148-150; 
in  exposition  of  processes,  203 

Dignity,  in  business  letters,  396 

Domville-Fife,  Charles  W.,  Submarine  Construction,  222-232 

Drawings,  use  of,  17-19 

Dry  Sand  and  Cement  Mixture  vs.  Mortar  Bed  for  Wood  Block  Pave' 
ments,  student  theme  in  exposition  of  ideas,  268-269 


424  INDEX 

E 

Electrical  World,  A  Convenient  Method  for  Replacing  Series  Incan- 
descent Street  Lamps,  168-170 
Electric  Burglar-Alarm,  The,  technical  description  from  Popular 

Science  Monthly,  178-186 
Electric  Furnace,  The,  outline  of,  34 
Electric  Heating  Devices,  exposition  of  ideas  by  John  F.  Rcbert- 

son,  279-280 
Electric  Railway  Journal,  Sand-drying  Plant  of  the  Metropolitan 

Street  Railway,  New  York,  172-178 
Electroplating  Non-metallic  ObjectSf  student  theme  in  exposition  of 

processes,  213-215 
Elliptical  clause,  dangling,  109-110 
Emphasis,  in  sentences,  120-123 
Engineering  letters,  types  of,  404-408 
Engineering  Record,  Reading  Technical  Journals,  editorial  comment 

on  J.  W.  Alvord's  How  to  Use  the  Technical  Journal,  289-290 
English,  value  of,  to  practicing  engineer,  3-6 
Erecting  a  Tent,  exposition  of  a  process  by  Herbert  M.  Wilson,  220- 

222 
Evidence,  in  exposition  of  ideas,  258-260 
Experience,  statement  of,  in  letters  of  application,  405 
Exposition,  defined,  9 

F 

Factor  of  Safety  in  Mine  Electrical  Installations,  The,  H.  H.  Clark, 

outline  of,  42 
Fallacies,  logical,  in  exposition  of  ideas,  260-261 ;  in  reports,  354-355 
Fieldner,  A.  C.  and  Stanton,  F.  M.,  Methods  of  Analyzing  Coal  and 

Coke,  outline  of,  41-42 
Fluid  Differential  Gages,  student  report,  367-369 
Fundamental  image,  in  technical  description,  1 50-1 51 


Generalizations,  loose,  in  expositions  of  ideas,  260-261;  in  reports* 

354-355 
Gerund  phrase,  dangling,  108-109 
Going,  Charles  Buxton,  The  Origin  of  the  Industrial  System,  335-347 


INDEX  425 


Grammatical  structure  of  the  sentence,  79-88 
Graphic  representations,  value  of,  17-19 


H 


Hale,  George  EUery,  The  Construction  of  a  Large  Reflecting  Tele- 
scope, 233-241 

Heading,  in  business  letters,  398-399  ' 

Holmes,  George  C.  V.,  The  Steam  Engine,  186-197 

Honesty,  in  report  writing,  352 

How  Photographs  are  Made,  student  theme  in  exposition  of  pro- 
cesses, 204-205;  outline  (of  a  different  exposition  on  the 
same  subject),  36-38 

How  to  Use  the  Technical  Journal,  exposition  of  ideas  by  John  W. 
Alvord,  281-289 

Huxley,  Thomas  Henry,  his  care  in  composition,  14;  his  skill  in 
addressing  the  general  reader,  16;  The  Method  of  Scientific 
Investigation,  290-297 

Hydraulic  laboratory  reports,  367-373 

Hyphen,  use  of,  96-97 

I 

Ideas,  exposition  of,  principles,  26-27;  255-267 

Illustrations,  in  general,  17-19;  in  technical  description,  147-150; 
in  exposition  of  processes,  203 

Incomplete  statement,  in  sentences,  1 18-120 

Individuality,  in  business  letters,  396-397;  in  letters  of  application, 
406 

Information  reports,  defined,  348 

Inside  address,  in  business  letters,  399 

Inspection  trip  reports,  defined  and  discussed,  359-364 

Instruction,  letters  of,  407-408 

Instruction  for  Preparing  Trip  Reports,  issued  by  College  of  Civil 
Engineering,  University  of  Wisconsin,  360-364 

Interurhan  Electric  Traction  Systems;  Alternating  Current  vs.  Direct 
Current,  exposition  of  ideas  by  P.  M.  Lincoln,  309-317 

Introductions,  in  general,  46-49;  as  occasional  violations  of  unity, 
24;  to  announce  contents  of  exposition,  25;  in  technical 
descriptions,  152;  in  expositions  of  processes,  202;  in  expo- 
sitions of  ideas,  264-265;  in  business  letters,  401-402 


426  INDEX 

K 

Kreisinger,  Henry  and  Ray,  "Walter  T.,  Comparative  Tests  of  Run- 
of-Mine  and  Briguetted  Coal  on  the  Torpedo  Boat  Biddle, 
table  of  contents  of,  379-380 


Laboratory  reports,  defined  and  discussed,  358-359 

Language,  technical,  15-16 

Laying  of  Underground  Concrete  Conduits,  The,  outline  of,  36,  and 

student  theme  in  exposition  of  processes,  210-213 
Letter-heads,  good  form  in,  394 
Lettering  of  diagrams,  18 
Letter  of  transmittal,  377,  387-388 

Letters,  principles  of  business  letters,  392-408;  specimens,  409-420 
Leveling,  student  theme  in  exposition  of  processes,  205-207 
Lincoln,  P.  M.,  Interurban  Electric  Traction  Systems;  Alternating 

Current  vs.  Direct  Current,  309-317 
Lines,  use  of,  in  statistical  tables,  18 
Literature,  value  of  reading  good,  51 
Logical  agreement,  in  sentence  structure,  116-118 
Logical  reasoning,  in  expositions  of  ideas,  260-261;  in  reports,  354- 

355 


Making  of  Pig  Iron,  The,  student  theme  in  exposition  of  processes, 
208-209 

Manufacture  of  a  Mercury  in  Glass  Thermometer,  The,  student  theme 
in  exposition  of  processes,  209-210 

Margins,  use  of,  around  drawings,  18;  for  marginal  gloss,  19 

Mead,  Daniel  W.,  quoted,  15-16;  Report  on  the  Proposed  Hydro- 
electric Developments  on  the  Peshtigo  River  at  High  and  John- 
son's Falls,  385-391 

Mechanical  devices  in  writing,  17-19 

Mechanical  Filter,  The,  technical  description  by  Mansfield  Merri- 
man,  170-172 

Merriman,  Mansfield,  The  Mechanical  Filter,  170-172 


INDEX 


427 


Method   of  Scientific  Investigation,    The,   exposition   of   ideas   by 

Thomas  Henry  Huxley,  290-297 
Methods  of  Analyzing  Coal  attd  Coke,  F.  M.  Stanton  and  A.  C. 

Fieldner,  outline  of,  41-42 
Misplaced  modifiers,  in  sentences,  114-116 

N 

Narration,  defined,  8-9 ;  narrative  method  used  in  exposition  of  pro- 
cesses, 1985 
Neatness,  in  report  writing,  353*354 

O 

Omissions,  incorrect,  in  sentences,  1 18-120;  of  subject  of  verb  in 

business  letters,  403 
Only,  misplacing  of  adverb,  115 
Opinion,  expositions  of,  2575 
Order  letters,  407 

Order  of  parts,  in  a  sentence,  114-116 
Orifice,  The,  student  reports,  369-373 
Origin  of  the  Industrial  System,  The,  exposition  of  ideas  by  Charles 

Buxton  Going,  335-347 
Outlines,  value  and  use  of,  in  planning  papers,  27-32;  examples  of, 

32-43 
Outside  correspondence,  specimens  of,  416-420 


Paper,  size  and  quality  of,  in  business  letters,  394 

Paragraph,  length  of,  54-55;  specimens  of,  57-58,  61-62,  66-76; 
principles  of  division  of,  55-62;  unity  of,  61-62;  internal  or- 
ganization of,  62-69;  ill  business  letters,  400-401 

Parallelism,  in  sentences,  104-107 

Parenthesis  marks,  use  of,  95-96 

Participial  phrase,  at  conclusion  of  business  letters,  402-403 

Parts  of  speech,  enumerated  and  defined,  86-87 

Period,  use  of,  89-95;  period  fault,  94 

"Personal  touch,"  in  business  letters,  396-397 

Photographs,  use  of,  in  technical  description,  147-150 


428  INDEX 

Phrase,  adjective-,  82-83,  87;  adverb-,  82-83,  87;  dangling  parti- 
cipial, 107-108;  dangling  gerund,  108-109;  participial,  at 
end  of  business  letter,  402-403 

Point  of  contact,  in  letters  of  application,  405 

Point  of  view  of  reader,  in  general,  12-17;  in  report  writing,  356-357 

Popular  Science  Monthly,  The  Electric  Burglar- Alarm,  178-186 

Post  hoc  fallacy,  in  expositions  of  ideas,  261;  in  reports,  355 

Predicate,  of  a  sentence,  8off 

Predication,  defined,  80 

Processes,  exposition  of,  9-10,  26,  198-203 

Professional  letters,  specimens  of,  413-420 

Professional  reports,  specimens  of,  377-391 

Progress  reports,  defined,  348 

Promptness,  in  report  writing,  351 

Proportion,  in  the  whole  composition,  44-45 

Proposed  Hydro-electric  Developments  on  the  Peshtigo  River  at  High 
and  Johnson's  Falls,  Report  on  the,  Daniel  Mead,  table  of 
contents,  letter  of  transmittal,  and  introductory  sections, 

385-391 
Proposed  Reorganization  of  an  Electrical  Testing  Laboratory,  outline 

of,  39-41 
Propositions,  in  expositions  of  ideas,  2566? 
Punctuation,  defined,  88;  discussed  and  illustrated,  88-97 


Qualifications,  statement  of,  in  a  letter  of  application,  405 
Question  mark,  use  of,  95 
Quotation  marks,  use  of,  96 


Rate  of  Burning  of  Fuse,  as  Influenced  by  Temperature  and  Pressure, 

The,  Walter  O.  Snelling  and  Willard  C.  Cope,  outline,  41, 

and  first  part  of,  381-385 
Rating  a  Water-current  Meter,  outline  of,  35-36 
Ray,  Walter  T.  and  Henry  Kreisinger,  Comparative  Tests  of  Run- 

of-Mine  and  Briquetted  Coal  on  the  Torpedo  Boat  Biddle, 

table  of  contents  of,  379-380 
Reading,  effect  of,  on  style,  51 


INDEX 


429 


Reading  Technical  Journals^  editorial  from  Engineering  Record  on 
John  W.  Alvord's  How  to  Use  the  Technical  Journal,  289-290 

Recommendation  reports,  defined,  348 

References,  in  letters  of  application,  405-406 

Refining  Crude  Petroleum,  exposition  of  a  process  by  Walter  Sheldon 
Tower,  241-254 

Reports,  principles  of,  348-365;  specimens  of,  366-391 

Research  reports,  defined,  348-349 

Robertson,  John  F.,  Electric  Heating  Devices,  279-280 

Running  a  Line  over  a  River,  introduction  of,  48 

Ruskin,  John,  quoted,  99 


Salutation,  in  business  letters,  399-400 

Sand  and  Mortar  Cushions  for    Wood    Block    Pavements,    student 

theme  in  exposition  of  ideas,  269-270 
Sand-drying  Plant  of  the  Metropolitan  Street  Railway,  New  York, 

technical  description  from  Electric  Railway  Journal,  172-178 
Sanderson  X-ray  Machine,  The,  outline  of,  38-39 
Semicolon,  use  of,  89-95 
Sentence,  grammatical  structure  of,  79-88;  punctuation  of,  88-97; 

rhetorical  structure  of,  97-123;  defective  and  weak  sentences 

for  revision,  123-140 
Signature,  in  business  letters,  402-403 
Simple  sentence,  defined,  83,  87 
Sketches,   in   general,    17-19;  in  technical  description,    148-150; 

in  exposition  of  processes,  203 
Slichter,  Charles  S.,  Suggestions  on  the  Study  of  Mathematics,  216- 

220 
Snelling,  Walter  O.  and  Willard  C.  Cope,  The  Rate  of  Burning  of 

Fuse,  as  Influenced  by  Temperature  and  Pressure,  outline, 

41,  and  first  part  of,  381-385 
Solution  of  Problems,  The,  student  theme  in  exposition  of  ideas,  272- 

274 
Spacing  Mechanism  of  the  L.  C.  Smith  Typewriter,   The,  student 

theme  in  technical  description,  158-160 
Speed  Counter,  The,  student  theme  in  technical  description,  157-153 
Staff  correspondence,  specimens  of,  413-415 
Standardization,  in  business  letters,  393 


430  INDEX 

Standard  Student  Lamp,  A,  student  theme  in  technical  description, 

160-161 
Stanton,  F.  M.  and  Fieldner,  A.  C,  Methods  of  Analyzing  Coal  and 

Coke,  outline  of,  41-42 
Steam  Engine,  The,  technical  description  by  George  C.  V.  Holmes, 

186-197 
Stones  of  Venice,  John  Ruskin,  quotation  from,  99 
Street  Lighting,  abstract  of  report  of  committee  on,  378-379 
Strength  of  Cement  Mortar,  introduction  of,  49 
Student  letters,  specimens  of,  409-413 
Student  reports,  defined,  349;  classified  and  discussed,   357-365; 

specimens  of,  366-376 
Style,  51-52 
Subject,  of  a  sentence  80;  of  a  paragraph,  63-64;  of  an  exposition, 

20-21 
Submarine  Construction,  exposition  of  a  process  by  Charles   W. 

Domville-Fife,  222-232 
Subordination,  in  sentences,  101-104 
Sub-titles,  in  general,  19;  in  reports,  357 
Suggestions  on  the  study  of  Mathematics,  exposition  of  a  process  by 

Charles  S.  Slichter,  216-220 
Suggestions  to  Authors,  quoted,  28,  47 


Table  of  contents,  in  reports,  357 

Table  of  Single  Potentials,  The,  student  theme  in  exposition  of 

ideas,  270-272 
Tables,  use  of  statistical,  17-19;  use  of,  with  diagrams,  18 
Technical  journals,  use  of,  in  thesis  writing,  364 
Telephone  Service  in  America,  exposition  of  ideas  by  John  J.  Carty, 

317-335 
Theses,  defined  and  discussed,  364-365 
Titles,  of  technical  papers,  45-46;  of  diagrams  and  sketches,  18; 

of  persons  and  firms  in  business  letters,  399 
Topics,  planning  by,  in  exposition  of  ideas,  262-264 
Tower,  Walter  Sheldon,  Refining  Crude  Petroleum,  241-254 
Transition  devices,  in  the  whole  composition,  43-44;  in  the  para- 
graph, 65-66;  in  exposition  of  ideas,  263-264 
Transitive  verbs,  defined,  81 


INDEX  431 

Transmittal,  letters  of,  377,  387-8 
Trip  reports,  defined  and  discussed,  359-364 
Two-cycle  Gas  Engine,  The,  outline  of,  34-35 
Typewriting,  in  business  letters,  394 

U 

Unity,  of  the  whole  composition,  22-25;  of  the  paragraph,  61-62; 

of  the  sentence,  98-101 
University  of  Wisconsin,  Instructions  for  Preparing  Trip  Reports, 

360-364 


Value  of  Technical  Journalistic  Work  to  the  Engineering  Student,  The, 
student  theme  in  exposition  of  ideas,  276-278 

W 

Weak  emphasis,  in  sentences,  120-123 

Weak  reference  of  pronouns,  11 2-1 14 

Web-foot  Engineer,  The,  exposition  of  ideas  by  Benjamin  Brooks, 

297-308 
Whole  composition,  the,  20-52 
Wilson,  Herbert  M.,  Erecting  a  Tent,  220-222 
Words,  use  of  technical,  15-16 


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